X-ray image of Perseus black hole region.

As astronomers struggle to understand dark matter, they keep pushing up against a contradiction of evidence. While there is a great deal of indirect evidence for dark matter within galaxies and galactic clusters, there is as yet no direct evidence of dark matter particles. Even worse, the standard model of particle physics, which accurately predicts the particles we observe, has no room for any undiscovered particle that could be dark matter.

For this and other reasons, theorists have proposed extensions of the standard model with an even larger range of theoretical particles. It's an effort to create some grand theory of everything. One popular extension includes a type of particle known as axions.

Axions are pretty controversial in physics. Theorists tend to like them because they would solve some bothersome issues with quantum theory. Some astronomers like them because some axions behave just like cold dark matter. Many experimentalists don't like them because there is some evidence to disprove them. Measurements of nuclear spin have eliminated many axion models, and spectral observations of galaxies rule most of them out as a candidate for dark matter.

But axions would be so gosh darn useful that as soon as one type of axion is ruled out folks start looking for the ones that haven't been eliminated. That's where a new study comes in. This one is a bit different because it uses distant galaxies to do particle physics.

If axions exist, then they would be produced by high energy interactions. These are the kind of interactions produced in particle accelerators, but they also occur naturally near black holes. So the team looked at x-ray signals coming from an active black hole in the galaxy NGC 1275.

Because axions would have more mass than known particles within the standard model, they should decay into lighter particles. Very low mass axions would decay directly into photons with specific wavelengths. So the team looked at the spectral pattern of x-rays from NGC 1275, and found no evidence for axions. So more axion models are ruled out, though as the authors point out there are still some axion models that haven't been disproven.

So once again it looks like axions don't exist. This goes to show that no matter how elegant your model is, it can still be completely wrong.

Reference: Abel, Christopher, et al. "Search for axionlike dark matter through nuclear spin precession in electric and magnetic fields." Physical Review X 7.4 (2017): 041034.

Reference: Ajello, M., et al. "Search for spectral irregularities due to photonaxionlike-particle oscillations with the Fermi Large Area Telescope." Physical Review Letters 116.16 (2016): 161101.

Reference: Reynolds, Christopher S., et al. "Astrophysical limits on very light axion-like particles from Chandra grating spectroscopy of NGC 1275." The Astrophysical Journal 890.1 (2020): 59.

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Astronomers Rule Out A Theory Of Everything - Forbes

Different photon paths create layers of light.

The supermassive black hole in M87 has a mass of more than 6 billion Suns. It is so large that its event horizon could easily swallow our entire system. It is also 53 million light-years away, which makes it rather difficult to observe. Its apparent size is similar to that of a baseball placed on the surface of the Moon.

To observe such a distant and faint object, it took an international team of radio astronomers. They tied together observatories from all over the world through a process known as interferometry, and created a virtual telescope nearly the size of Earth. Months of gathered data then had to be shipped to computational facilities where the data was processed to create the first direct image of a black hole.

The first image of a supermassive black hole.

While this was a monumental achievement, the image itself seemed rather unimpressive to some. That's it? All this work for a blurry image with a dark center? What does that tell us about a black hole? Like most radio images, looks can be deceiving. While the black hole image is great for a bit of press, it's just how we represent the radio data in a visually appealing way.

Even this processed image isn't an image of the black hole itself. Black holes don't emit light, so they are effectively invisible. What this image represents is light that has been gravitationally focused in our direction, kind of like the headlight of a car. The black hole is bathed in a glow of radio light, and when some of the light passes close to the black hole the direction changes radically. The only light we see is the light deflected along our line of sight. The dark region is the shadow cast by the black hole within the radio glow.

From this first data astronomers were able to pin down some of the black hole properties, such as its mass and rotation. Of course, astronomers would like to learn even more, which is a challenge given that even this blurry image pushed the limits of our technology. But a new paper published in *Science Advances* shows how it might be done.

When a black hole is surrounded by hot gas, light can be focused by gravity to create a shadow of ... [+] the black hole.

The key is to understand how light is deflected near a black hole. While a black hole deflects light like a lens, it does so in rather odd ways when the light gets really close. The most common deflection is for the path of light to simply change direction. This is most of the light we see in the black hole image. But get a little closer, and the light can orbit the black hole once before being sent on its way. A bit closer, and it can orbit two times, or three times.

Light taking an ever-closer approach can reach a point where light orbits the black hole indefinitely. Photons can orbit a black hole similar to the way planets orbit a star. This orbit region for light is known as the photon sphere. It marks the limit of a stable orbit around a black hole. General relativity makes strong predictions about the size and shape of the photon shell. If we can observe it, we could test relativity in new ways.

This new research shows how all these different paths are contained in the radio data we gather, and how these layers create distinct signatures within interferometry. In other words, to observe the photon sphere, we don't need to create ever-sharper images of a black hole. Instead, we can look for these signatures to pull out the data of each layer.

At the moment this technique is beyond the ability of the current Event Horizon Telescope, but it does show how further advances in radio astronomy could lead to a much greater understanding of black holes.

Reference: Johnson, Michael D., et al. "Universal Interferometric Signatures of a Black Hole's Photon Ring." Science Advances Vol. 6, no. 12, (2020).

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How Astronomers Could Sharpen The Image Of A Black Hole - Forbes

Astrophysicists using NASAs Chandra X-ray Observatory have looked for signs of an as-yet undetected particle predicted by string theory, a set of models intended to tie together all known forces, particles, and interactions.

Reynolds et al used Chandra to look for extraordinarily low-mass axion-like particles in the Perseus galaxy cluster, a group of galaxies located 240 million light-years away from Earth. The observation lasting over five days showed no evidence for certain axion-like particles, which some theorists think can explain dark matter. The lack of detection in these Chandra observations helps rule out some versions of string theory, a set of models intended to tie together all known forces, interactions, and particles. Image credit: NASA / CXC / University of Cambridge / Reynolds et al.

Until recently I had no idea just how much X-ray astronomers bring to the table when it comes to string theory, but we could play a major role. If these particles are eventually detected it would change physics forever, said studys lead author Dr. Christopher Reynolds, a researcher at the University of Cambridge.

The particle that Dr. Reynolds and colleagues were searching for is called an axion.

This as-yet-undetected particle should have extraordinarily low mass. Theoretical physicists do not know the precise mass range, but many theories feature axion masses ranging from about a millionth of the mass of an electron down to zero mass.

Some scientists think that axions could explain the mystery of dark matter, which accounts for the vast majority of matter in the universe.

One unusual property of this ultra-low-mass particle would be that it might sometimes convert into photons (that is, packets of light) as they pass through magnetic fields. The opposite may also hold true: photons may also be converted into axions under certain conditions.

How often this switch occurs depends on how easily they make this conversion, in other words on their convertibility.

Some scientists have proposed the existence of a broader class of ultra-low-mass particles with similar properties to axions.

Axions would have a single convertibility value at each mass, but axion-like particles would have a range of convertibility at the same mass.

While it may sound like a long shot to look for tiny particles like axions in gigantic structures like galaxy clusters, they are actually great places to look, said studys co-author Dr. David Marsh, a researcher at Stockholm University.

Galaxy clusters contain magnetic fields over giant distances, and they also often contain bright X-ray sources. Together these properties enhance the chances that conversion of axion-like particles would be detectable.

To look for signs of conversion by axion-like particles, the astrophysicists examined over five days of Chandra observations of X-rays from material falling towards the supermassive black hole in the center of NGC 1275, the central galaxy of the Perseus galaxy cluster.

They studied the Chandra spectrum, or the amount of X-ray emission observed at different energies, of this source.

The long observation and the bright X-ray source gave a spectrum with enough sensitivity to have shown distortions that scientists expected if axion-like particles were present.

The lack of detection of such distortions allowed the researchers to rule out the presence of most types of axion-like particles in the mass range their observations were sensitive to, below about a millionth of a billionth of an electrons mass.

Our research doesnt rule out the existence of these particles, but it definitely doesnt help their case, said studys co-author Dr. Helen Russell, a researcher at the University of Nottingham.

These constraints dig into the range of properties suggested by string theory, and may help string theorists weed their theories.

The results appear in the Astrophysical Journal.

_____

Christopher S. Reynolds et al. 2020. Astrophysical Limits on Very Light Axion-like Particles from Chandra Grating Spectroscopy of NGC 1275. ApJ 890, 59; doi: 10.3847/1538-4357/ab6a0c

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Astrophysicists Perform Test of String Theory | Astronomy - Sci-News.com

develoPPP.de CLASSIC Development partnerships with the private sector

BMZ can support your companys innovative projects and commercial investments in developing and emerging-market countries provided that they offer long-term benefits for the local population.

Projects typically cover a wide range of sectors and themes from training local experts and piloting innovative technologies and demonstration units to protecting value chains and improving manufacturers environmental and social standards.

Target groupCompanies with project ideas that offer potential development benefits and do not simply constitute an investment in theiractual core business.

FundingBetween EUR 100,000 and EUR 2 millionof public funding on top of your companys own contribution ( 50%)

CriteriaMinimum annual turnover: EUR 800,000Minimum number of employees: 8At least two years of audited financial statements

TermUp to three years

Click BMZ Offers Financial And Technical Support To Public & Private Companies to apply and get further information.

Startups and SMEs With Innovative Solutions To Submit Application To Tackle Coronavirus Outbreak

The European Commission is calling for startups and SMEs with technologies and innovations that could help in treating, testing, monitoring or other aspects of the Coronavirus outbreak to apply urgently to the next round of funding from the European Innovation Council.

With a budget of 164m,this callis bottom-up, that is, there are no predefined thematic priorities and applicants with Coronavirus relevant innovations will be evaluated in the same way as other applicants. Nevertheless, the Commission will look to fast track the awarding of EIC grants and blended finance (combining grant and equity investment) to Coronavirus relevant innovations, as well as to facilitate access to other funding and investment sources.

The EIC is already supporting a number of startups and SMEs with Coronavirus relevant innovations awarded funding in previous rounds. This includes theEpiShuttle projectfor specialized isolation units and them-TAP projectfor filtration technology to remove viral.

The deadline for applications to theEIC Acceleratoris17:00 on Friday 20 March (New deadline)(Brussels local time).

Click Startups and SMEs With Innovative Solutions To Submit Application To Tackle Coronavirus Outbreak to apply and get further information.

NewSpace Systems is Hiring A Design Engineer & Product Support Engineer; Apply

NewSpace Systems, the product development, and manufacturing aerospace engineering company in Somerset West is looking for a Design Engineer & Product Support Engineer to work in Somerset West, Western Cape, permanently.

DESIGN ENGINEER(Somerset West, Western Cape 7130, Permanent)

A permanent position for a design engineer to take responsibility for new electro-mechanical product design, development, and verification on various projects working within a multidisciplinary team.

Qualifications:

B.Sc/B.Eng degree in Engineering (preferably electronic, mechanical or mechatronic) from a recognized institution.

Experience (ideally within aerospace or defence industry):

High-reliability electronic product design, realization, and environmental testing(>3 years)

Additional knowledge areas that would strengthen the application

PRODUCT SUPPORT ENGINEER(Somerset West, Western Cape 7130, Full-time, Permanent)

A permanent position for a product support engineer to take responsibility for the industrialization, support, customization, and improvement of Companys products and processes.

Qualifications:

Experience (ideally within aerospace or defence industry):

(Preferably in Solid Works)

Click NewSpace Systems is Hiring A Design Engineer & Product Support Engineer; Apply to apply and get further information.

SANSA Calls For A Space Weather Project Lead; Apply Now

The South African National Space Agency requires a project specialist for a period of three years to apply sound project management principles to the operational space weather centre project (hereafter called the project) the aim of the project is to move the limited operational space weather centre to a full 24/7 operational centre with all the identified products and services in place, the capability and knowledge strengthened and the required certification (which includes ISO 9001:2015) achieved. The project has already started and a number of mechanisms have already been applied. The incumbent will need to take these over and ensure continuity.

The space weatherproject leadwill be required to plan, budget, oversee and document all aspects of this project. The project lead will have the overall responsibility for the successful planning, design, execution, monitoring, controlling and closure of the project. The successful incumbent will also be required to assist in developing a marketing strategy and exploring funding opportunities for the centre.

Responsibilities will include:

Closing date: 24 March 2020

Click SANSA Calls For A Space Weather Project Lead; Apply Now to apply and get further information.

Registration Open To Participate In The 2020 Farming by Satellite Prize

The Farming by Satellite Prize rewards young innovators exploring the use of satellite technologies to improve agriculture and reduce environmental impact. Applications for the 2020 Prize open 16 March.

Kicking off its 5th edition, the Farming by Satellite Prize is designed to encourage young professionals, farmers and students in Europe and Africa to create new, sustainable and environmentally friendly solutions using Copernicus, EGNOS and Galileo. A total Prize pool of 10,000 is up for grabs in 2020 with prizes distributed among the top three European applicants as well as the best idea submitted to the Special Africa Prize. Returning this year, the Special Africa Prize encourages young Africans to seek satellite-based solutions for their agricultural needs.

How does it work?

Each team nominates a leader to register their team and idea on the application platform. Once registered, teams can start on their applications and return to the platform to keep working on their ideas until the deadline of 15 June. All applications will then be evaluated, and the top finalists will be selected to continue to the deep dive phase. This next phase will see teams submit a pitch deck to compete for the chance to travel to the live pitch and award ceremony event. Two phases, live pitching, and 10k up for grabs.

Who can participate?

Individuals or teams of up to four people are invited to register online between 16 March and 15 June 2020. All team members must be under the age of 32 by the submission deadline and be a citizen or resident of a European or African country. All applicants must be at least of 18 years of age by the date of application submission deadline.

The prize

1st place 5,0002nd place 3,0003rd place 1,000

Special Africa Prize 1,000

And an expenses-paid trip to participate in the final stage of the competition, and the Award Ceremony. A group of expert judges will review every idea.

Event Date (estimated)1 Announcement of Contest 16 March 20202 Deadline Open Call (First Phase) 15 June 20203 Announcement of the results of Open Call (First Phase) 30 June 20204 Deadline Deep Dive Phase (Second Phase) 30 September 20205 Announcement of the Deep Dive results 16 October 20206 Final step Live Pitches & Awards Ceremony November-December 2020

Click Registration Open To Participate In The 2020 Farming by Satellite Prize to apply and get further information.

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Weekly Round-Up Of Space And Astronomy Opportunities For Africans - Space in Africa

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: the study of objects and matter outside the earth's atmosphere and of their physical and chemical properties

Some may find it easy to confuse astronomy and astrology. At one time, these two words actually were synonymous (that is, astronomy once meant what astrology means today), but they have since moved apart from each other. In current use, astronomy is concerned with the study of objects and matter outside the earth's atmosphere, while astrology is the purported divination of how stars and planets influence our lives. Put bluntly, astronomy is a science, and astrology is not.

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'astronomy.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

12th century, in the meaning defined above

Middle English astronomie, from Anglo-French, from Latin astronomia, from Greek, from astr- + -nomia -nomy

Cite this Entry

Astronomy. Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/astronomy. Accessed 11 Mar. 2020.

More Definitions for astronomy

: a science concerned with objects and matter outside the earth's atmosphere and of their motions and makeup

Comments on astronomy

What made you want to look up astronomy? Please tell us where you read or heard it (including the quote, if possible).

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Astronomy | Definition of Astronomy by Merriam-Webster

After a 40-year search, astronomers have spotted a first-of-its-kind star that pulsates on just one side.

Amateur astronomers played an important role in the discovery by trawling through data from NASAs planet-hunting Transiting Exoplanet Survey Satellite (TESS).

The one-sided pulsator was spotted in the Milky Way about 1,500 light-years from Earth, according to researchers. A light-year, which measures distance in space, equals about 6 trillion miles.

17-YEAR-OLD NASA INTERN MAKES STUNNING DISCOVERY

The star, which is known as HD74423, is about 1.7 times the mass of the Sun.

An artist's impression of the star and its red dwarf "companion". (Gabriel Prez Daz, IAC)

An international team of astronomers harnessed a wealth of data to make the discovery. Their research is published in the journal Nature Astronomy.

"What first caught my attention was the fact it was a chemically peculiar star," said co-author Simon Murphy, Ph.D.from the Sydney Institute for Astronomy at the University of Sydney, in a statement. "Stars like this are usually fairly rich with metals - but this is metal poor, making it a rare type of hot star."

77-YEAR-OLD AMATEUR ASTRONOMER HELPS MAKE STUNNING DISCOVERY

Other astronomers had also started to study the star. "We've known theoretically that stars like this should exist since the 1980s," the study's co-author, Don Kurtz, who is from the U.K.s University of Central Lancashire, said in the statement.

"I've been looking for a star like this for nearly 40 years and now we have finally found one," added Kurtz, who is also the inaugural Hunstead Distinguished Visitor at the University of Sydney.

While astronomers have known about pulsating stars for a long time, stars that oscillate over just one hemisphere are a new phenomenon. HD74423, the researchers explain, is in a binary star system with a red dwarf, or small, cool star. Its close companion distorts the oscillations with its gravitational pull, the researchers explained, in the statement. The clue that led to its discovery came from citizen scientists poring over public data from NASA's TESS satellite, which is hunting for planets around distant stars.

GIANT BLACK HOLE 'SHOULD NOT EVEN EXIST,' STUNNED SCIENTISTS SAY

Because the orbital period of the binary system is less than two days, HD74423 is being distorted into a teardrop shape by the red dwarfs gravitational pull.

"The exquisite data from the TESS satellite meant that we could observe variations in brightness due to the gravitational distortion of the star as well as the pulsations, said ProfessorGerald Handler from the Nicolaus Copernicus Astronomical Centre in Poland, who is the studys lead author.

Experts believe that other similar stars exist.

NASAS SOLAR ORBITER SET FOR HISTORIC MISSION TO THE SUN

The pulsating star is the latest in a series of fascinating discoveries by astronomers across the globe.

In another project, for example, a 77-year-old amateur astronomerrecently helped discover a rare galaxy double nucleus. Allen Lawrence, a retired electrical engineer, used infrared images from NASAs Wide-field Infrared Survey Explorer to reveal the double nucleus galaxy.

NASA also recently announced that a 17-year-old summer intern made an incredible planet discovery. Wolf Cukier, a student from Scarsdale High School in New York, had just finished his junior year when he started his internship at NASAs Goddards Space Flight Center in Goddard, Md., last summer. Within just a few days, he made an incredible find while sifting through variations in star brightness captured by the space agencys Transiting Exoplanet Survey Satellite (TESS) uploaded to the Planet Hunters TESS citizen science project.

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A signal from a distant system called TOI 1338 turned out to be a planet. The planet, TOI 1338 b, is the first circumbinary planet, or world orbiting two stars, that has been spotted using TESS data.TOI 1338 b is about 6.9 times larger than Earth, which means that it is between the size of Saturn and Neptune.

Follow James Rogers on Twitter @jamesjrogers

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Amateur astronomers help discover incredible teardrop-shaped star - Fox News

The four fundamental forces

Physics textbooks teach that there are four fundamental forces of nature: gravity, electromagnetism, and the strong and weak nuclear forces.

Were quite familiar with the first two forces. Gravity pins us to Earth and pulls us around the sun, while electromagnetism keeps the lights on. The other two forces are less obvious to us because they govern interactions at the tiniest scales. The strong force binds matter together, while the weak nuclear force describes the radioactive decay of atoms.

Each of these forces is carried by a kind of subatomic particle that physicists call a boson. For example, photons are the force particle in electromagnetism. Gluons carry the strong nuclear force. W and Z bosons are responsible for the weak nuclear force. Theres even a hypothetical boson for gravity called the graviton, though scientists havent proven its existence.

However, if you ask many theoretical physicists, theyll probably tell you we havent discovered all the forces of nature yet. Others are likely out there, just waiting to be discovered.For example, some suspect that discovering dark matter may reveal a weak new force.

And thats where the Hungarian group comes in. Without getting too lost in the details, the group shot protons at a thin sample of lithium-7, which then radioactively decayed into beryllium-8. As expected, this created pairs of positrons and electrons. However, the detectors also picked up excess decay signals that suggested the existence of a potential new and extremely weak particle. If it exists, the particle would weigh in at about 1/50 the mass of a proton. And because of its properties, it would be a boson a force-carrying particle.

But history is littered with reasons to be skeptical of new additions. In recent decades, other groups have also claimed to have found a fifth force, only to have their claims quietly fade away. Around the year 2000, one group proposed a new force, called quintessence, to explain the then-recent discovery of dark energy. In the 1980s, a group of physicists at MIT said theyd found a fifth force, dubbed hypercharge, that served as a kind of anti-gravity. Yet here we are with textbooks still teaching the same four fundamental forces we had decades ago.

That means the most likely explanation for the unexplained new signal is that theres something off with the Hungarian detectors setup. However, no one is disputing the data. The findings were peer-reviewed and published in the journal Physical Review Letters the same journal that published the discovery of gravitational waves. Even ideas in prestigious journals can sometimes be explained away as systematic error, but thats the way science works.

People are paying attention to see whether this is really a nuclear physics effect or whether its something systematic, Alves says. Its important to repeat those experiments ... to be able to test whether this is real or if its an artifact of the way theyre doing the experiment.

Quest to confirm

And thats precisely what her group hopes to do. Together with a small team, shes proposing to repeat the Hungarian experiment using equipment that already exists at Los Alamos. The national lab has been a leader in nuclear physics since the creation of the atomic bomb. And today, thousands of top physicists still work there on problems ranging from safeguarding and studying our nations nuclear arsenal, to pioneering quantum computers and observing pulsars.

As it turns out, they also have a detector nearly identical to the one used by the Hungarian team.

When you add all that together, Alves believes Los Alamos has exactly the right combination of facilities and expertise to repeat the experiment. Thats why her group quietly worked on their proposal for the last six months, and recently submitted a funding request for review. To gain approval, it will have to win out in an annual competition alongside other projects at the national lab.

In recent years, several other groups likewise have suggested theyll look for this force. But at the moment, Alves believes they're the main group in the U.S. working to confirm or refute the finding. If they cant gain approval, it may be years before a university or other group can secure both the funds and expertise to repeat the experiment with the same sort of parameters the Hungarians used.

As with all extraordinary claims, this potentially paradigm-shifting discovery will require extraordinary evidence before people accept it. So we may have to wait a while before we know whether the X17 particle and its potential fifth force will revolutionize physics, or take its place atop the dustbin of debunked and discarded discoveries.

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The fifth force: Is there another fundamental force of nature? - Astronomy Magazine

Friday, March 6A waxing Moon hangs out in Cancer the Crab all night. About 18 to its west is yellowish Pollux in Gemini, and nearly 4 farther is the whiter-hued Castor. The latter appears to the naked eye as a magnitude 1.6 star, but it is actually a six-star system. The two brightest stars, Castor A and B, can be separated with a small telescope.A third component, the dimmer Castor C, lies about 1.2' away.

Saturday, March 7Night owls can take a gander at one of the best globular clusters visible in the Northern Hemisphere. Messier 13, also known as the Hercules Cluster, rises above the horizon with its namesake constellation about 9 P.M. local time but is well poised for clearer viewing by midnight and into the early hours of the morning. This cluster of ancient stars circling our galaxy contains more than 100,000 members that combine to create its magnitude 5.8 glow.

Sunday, March 8Venus and Uranus lie just over 2 apart in the evening sky. You can use Venus to easily find the ice giant by using binoculars or a telescope to locate a pair of 7th-magnitude stars about 1.2 to the lower left of Venus. Travel twice that distance in the same direction to reach brighter Uranus, glowing at magnitude 5.9.

Neptune is in conjunction with the Sun at 8 A.M. EDT. However, its position means it is lost from view in the bright glare of our star. It will make its way back to visibility by the end of next month.

For most of the United States and Canada, daylight saving time begins at 2 A.M. local time this morning. Set your clocks ahead one hour.

Monday, March 9Venus passes 2 north of Uranus this morning at 11 A.M. EDT. The inferior planet will continue to move noticeably through Aries as March progresses, while the more distant ice giant moves only about 1 eastward during the month.

Mercury is stationary at 4 A.M. EDT. From here, it will move toward its greatest western elongation, which it will reach on the 23rd.

The Full Moon occurs at 1:48 P.M. EDT. This evening, our satellite rises in Virgo as the Sun is setting and will set in the morning around dawn. Full Moon is an excellent time to easily observe Luna with or without additional optical assistance; keep in mind that the Moon will appear especially bright through binoculars or a telescope. The Full Moon also washes out much of the sky, making this time best for observing planets and brighter stars, but poor for deep-sky objects such as galaxies and nebulae.

Tuesday, March 10The Moon reaches perigee, its closest point to Earth in its orbit, at 2:30 A.M. EDT. At that time, it will sit 221,905 miles (357,121 kilometers) from our planet.

When the Full Moon occurs at perigee, it is sometimes called a supermoon by the media. Although this is an evocative name, the Full Moon will only appear about 7 percent larger than average, which is difficult if not impossible for observers to discern.

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The Sky This Week from March 6 to 13 - Astronomy Magazine

Three teams of astronomers have been fascinated by an alien world known as K2-18b. But what's all the fuss about?

In September, two teams announced that they had found signs of liquid water in the planet's atmosphere a landmark discovery in the search for potentially habitable alien worlds. But the mere presence of water isn't the only condition necessary for life. Other conditions, like temperature and pressure, can also affect a planet's habitability. Now, a third team reports that the pressures of liquid water on the same world may be good for life to evolve another intriguing development for scientists.

"We recognized pretty early on that this is a very unique target," Bjrn Benneke, an astronomer at the University of Montreal, told Space.com. Benneke led one of the teams that announced the atmospheric analysis in the September 2019 study, which was published in The Astrophysical Journal Letters in December. He presented the findings in January at a meeting of the American Astronomical Society.

Related: 7 ways to discover alien planets

Benneke and his colleagues used the Hubble and Spitzer space telescopes to study K2-18b a dozen times over a three-year period, to collect precise observations of its atmosphere.

Although scientists have studied exoplanet atmospheres before, those worlds have been larger than K2-18b, which is only about 2.6 times the size of Earth and 8.5 times its mass. The planet's small size made the observations especially challenging, requiring multiple detailed measurements that, combined, could provide a more in-depth probe of the world.

"Nothing like this has been done before," Benneke said.

K2-18b is 110 light-years away, in the constellation Leo, where it orbits a small but active type of star that can hurl bursts of radiation at orbiting planets. Although the star is smaller and dimmer than the sun, K2-18b's 33-day orbit means the planet receives roughly the same amount of energy from its star as Earth receives from the sun.

The star's small size makes it easier to detect details of a diminutive planet like K2-18b because observations of a planet depend on how much light it blocks as it passes in front of its star from Earth's perspective. A smaller planet blocks less light than a larger one, but a smaller star has less light to block, making that small signal somewhat easier to see. (The planet's orbit also helped scientists capture multiple passes across its star.)

In the Hubble and Spitzer observations, Benneke and his team found the signature of water in the exoplanet's atmosphere and not just any form of water. "Even more exciting, we discovered in the data that there's a cloud deck on the planet," Benneke said.

The clue was that starlight beaming through the atmosphere came to an abrupt stop at a certain altitude. Benneke and his colleagues used models to determine that the height was the perfect pressure and temperature for water to survive.

"The only plausible explanation is that these are liquid water clouds, very similar to what we have on Earth," Benneke said.

As the clouds fill with water droplets, they most likely create rainfall. But that rain would never touch the ground. Instead, it would fall until temperatures and pressures caused it to evaporate once again, the researchers said. Benneke compared rainfall on K2-18b to terrestrial virga, which occurs when high temperatures and pressures cause rain to evaporate before it reaches the ground.

Finding a similar weather pattern on an exoplanet is an intriguing prospect to Benneke.

"[K2-18b] is the coldest planet with [atmospheric] detection, the smallest planet, the least-massive planet," he said. "To me, it's the most exciting one."

Although K2-18b has the right conditions for Earth-like clouds to form, that doesn't make the planet itself Earth-like. Instead, it is classified as a sub-Neptune, a gas giant without a surface. NASA's Kepler spacecraft determined that sub-Neptunes are likely the most common type of exoplanets in the Milky Way, making up more than three-fourths of the planetary population.

Nonetheless, astronomers are having a difficult time understanding the relatively small gas giants, and that's one reason the K2-18b findings are so exciting. "We don't quite know what's going on with these planets," Benneke said. "It's probing this regime of planets that we have a very poor understanding of right now."

Sub-Neptunes have masses that fall somewhere between Earth and Neptune, and there's no analogue in the solar system. Understanding worlds like K2-18b can help improve scientists' knowledge of how planets grow and evolve. "If you want to understand planets as a whole, the diversity of planets, it's very critical that you understand the most common ones," Benneke said.

Follow Nola Taylor Redd on Facebook and on Twitter at @NolaTRedd. Follow us on Twitter @Spacedotcom and on Facebook.

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This gas-giant exoplanet has water-rich clouds. Here's why it thrills astronomers. - Space.com

Hold on, a quick aside. When you say the word billion on the show, I feel like you think for a moment before you pronounce it. Were you careful in how you said the word billion, not to sound too much like Carl Sagan?

[laughs] You know, you can't step into a Sagan slot and not be conscious of the number billion. There were a couple of times I would punch it up a notch, almost as an homage, but otherwise not. I do remember a couple of times when I didn't think the editors would use those cuts where I went high on the intonation scale.

Sorry, back to our conversation. Many people who think about the future of humanity imagine us someday merging with computers. Does that seem credible to you?

No, not really. And I know I'm an outlier here. It doesn't feel credible because, you know, I have in my palm access to the internet. So you're saying, "Oh, now I'm going to wire that with a USB connection into my brainstem." How fast access am I going to want? Is it not fast enough to pull this phone out of my pocket? For me, the fact that it is right with me every day I leave the house, that doesn't leave me wanting this thing to be surgically connectedto get silicon surgically connected to my physiology.You dont crave more speed, more connection to information?

Heres a related analogy. Air transportation, in its early decades, was about how fast can you fly to your destination, how to minimize the time you're on an airplane. So planes got faster and faster. We got to jets instead of propellers, and then we got the supersonic transport. Then things started pulling back. Why? Well we had the 747. Planes got larger, they had better food, they had more leg room. The seats were more comfortable. Today we have the internet on your flight, we have any movie you'd ever want to watch, we have music.

The idea that speed was so important that we would want it at all costs gave way to a different idea: I am comfortable in this environment, and in fact I can even catch up on things. I can binge on shows I didn't have time to watch at home. You can come off the plane in a better place than you were before you entered it. And so no one is trying to make planes faster today. In fact, they're slower than before. The typical speeds are 500 to 550 miles per hour, whereas when I was growing up, the speeds were 600 to 650 miles per hour.

So to say we're going to become one with artificial intelligence because we want the speed, I just don't see that happening.

A lot of people also dream that computer technology will bring us immortality. Thats a possible world they long for: We will upload our brains, and then we'll never die.

Well, I would ask, if you upload your brain, how do you know that's still you? I don't think we understand consciousness enough to assert that. We can say that's your knowledge. That thing, that entity has all the same knowledge that you have, but is that you? I don't know.

We know that an identical twin has identical DNA to you yet they are not you. You don't have their thoughts and they don't have your thoughts. So this notion of uploading your consciousnessI'm not going to pay close attention to it until we have a secure understanding of what consciousness is in the first place.

That's a whole other mysterious world, the mental world that is still barely being explored.

Right. Its a frontier perhaps as vast as the universe itself.

Excerpt from:

Get ready to explore the "Cosmos" with Neil deGrasse Tyson - Astronomy Magazine

Get your friends together for Friends trivia this Tuesday

Think you have the unagi to participate in Friends Trivia at Reginellis Pizzeria Tuesday, March 10? Well, get your gang of one to six people together as you compete for Reginellis gift cards. And as always, the best team name wins a free pitcher of NOLA Blonde. Could you be any more excited? If so, be sure to share plenty of food while youre at it, too, because we all know Joey doesnt share food!

Reginellis Pizzeria (Goodwood) is at 684 Jefferson Highway.

Head over to Bin 77 Bistro & SideBar as the restaurant features Single Vineyard wines of the Hartford Court Family Winery on Tuesday, March 10. Besides two flights of white and red wine, there will also be plenty of chef and sommelier boards, starting at 7 p.m., which will include various cheeses, charcuteries and cooked proteins to go with the wines.

To make a reservation, call Bin 77 at 763-2288.

Bin 77 Bistro & SideBar is at 10111 Perkins Rowe, Ste. 160.

Curious about whether or not Experiment 626 and Chewbacca could exist, and what their lives might be like? You and your kids can find out as Astronomy on Tap celebrates its second anniversary Wednesday, March 11. LSU grad student Rachel Malacek will talk about the possible adventures of Stitch (from Lilo and Stitch), and fellow grad student Aaron Ryan will discuss the life of Chewbacca.

There will be plenty of games, raffles, glow sticks and spaced-themed drinks for everyone, too.

The Varsity Theatre is at 3353 Highland Road.

Need to wine down? Join Rouj Creole Wednesday, March 11, as the new restaurant hosts another wine dinner. You can enjoy the chefs four-course meal, included with a Duckhorn wine pairing, 6:30-9:30 p.m.

To make a reservation, call Rouj at 614-2400.

Rouj Creole is at 7601 Bluebonnet Blvd., Ste 100.

Join Red Stick Spice Co. as its team teaches you how to demystify pantry staples with Middle Eastern foods Thursday, March 12. You can look forward to tahini cookies, roasted eggplant, pomegranate molasses and more, 6-8 p.m.

This class is available for those 16 and older. Tickets are available here.

Red Stick Spice Company is at 660 Jefferson Highway.

Read more from the original source:

Dine Roundup: Wine dinners, Astronomy on Tap and more in Baton Rouge this week - 225 Baton Rouge

Are we alone in the Universe? The expert opinion on that, it turns out, is surprisingly consistent.

Is there other life in the Universe? I would say: probably, Daniel Zucker, Associate Professor of astronomy at Macquarie University, tells astrophysics student and The Conversations editorial intern Antonio Tarquinio on todays podcast episode.

I think that we will discover life outside of Earth in my lifetime. If not that, then in your lifetime, says his fellow Macquarie University colleague, Professor Orsola De Marco.

And Lee Spitler, a Senior Lecturer and astronomy researcher at the same institution, was similarly optimistic: I think theres a high likelihood that we are not alone in the Universe.

The big question, however, is what that life might look like.

Read more: The Dish in Parkes is scanning the southern Milky Way, searching for alien signals

Were also hearing from Danny C Price, project scientist for the Breakthrough Listen project scanning the southern skies for unusual patterns, on what the search for alien intelligence looks like in real life - and what its yielded so far.

Read more: 'The size, the grandeur, the peacefulness of being in the dark': what it's like to study space at Siding Spring Observatory

Everything you need to know about how to listen to a podcast is here.

Additional audio credits

Kindergarten by Unkle Ho, from Elefant Traks.

Lucky Stars by Podington Bear, from Free Music Archive

Illumination by Kai Engel, from Free Music Archive

Podcast episode recorded and edited by Antonio Tarquinio.

Shutterstock

See the article here:

We asked astronomers: are we alone in the Universe? The answer was surprisingly consistent - The Conversation AU

Observations of the star Betelgeuse taken by the ESOs Very Large Telescope in January and December ... [+] 2019, which show the stars substantial dimming.

Astronomers expect Betelgeuse to explode as a supernova within the next 100,000 years, when its core collapses. However, evidence is mounting that the stars dimming, which began in October, isnt necessarily a sign of an imminent explosion.

A new paperaccepted to Astrophysical Journal Letters and published on the preprint site arXiv entitled Betelgeuse Just Isn't That Cool: Effective Temperature Alone Cannot Explain the Recent Dimming of Betelgeuse by Emily Levesque, a UW associate professor of astronomy, andPhilip Massey, an astronomer with Lowell Observatory, suggests that Betelgeuse isnt dimming because its about to explode.

Its just dusty.

Astronomers have been on alert since late in 2019 when Betelgeusefound in the constellation of Orionbegan to visibly dim, eventually dropping to around 40% of its usual brightness before slightly brightening in recent weeks.

Could it be about to explode as a massive supernova?

Probably not. Levesque and Massey made optical spectrophotometry observations of Betelgeuse on February 14, 2020 at Lowell Observatory in Flagstaff, Arizona, to calculate the average surface temperature of the red supergiant star. Their results indicate that Betelgeuse is significantly warmer than expected if the recent dimming were caused by a cooling of the stars surface.

This evidence suggests that Betelgeuse has probably sloughed off some material from its outer layers, something that is common with red supergiant stars. We see this all the time in red supergiants, and its a normal part of their life cycle, said Levesque. Red supergiants will occasionally shed material from their surfaces, which will condense around the star as dust. As it cools and dissipates, the dust grains will absorb some of the light heading toward us and block our view.

The first direct image of a star other than our sun, taken with the Hubble Space Telescope. ... [+] Betelgeuse is an enormous star in the constellation Orion. This ultraviolet image shows a bright spot on the star that is 2000 degrees centigrade hotter than the rest of the surface. The picture on the right shows the constellation Orion, with Betelgeuse marked by a yellow cross. The star's size relative to the earth's orbit is also shown. (Photo by CORBIS/Corbis via Getty Images)

How do you take a stars temperature?

The astronomers calculated Betelgeuses temperature by looking at the spectrum of light emanating from it. Emily and I had been in contact about Betelgeuse, and we both agreed that the obvious thing to do was to get a spectrum, said Massey. I already had observing time scheduled on the 4.3-meter Lowell Discovery Telescope, and I knew if I played around for a bit I would be able to get a good spectrum despite Betelgeuse still being one of the brightest stars in the sky.

They looked for the telltale signs of light that had been absorbed by titanium oxide, which forms in the upper layers of large, relatively cool stars like Betelgeuse. By their calculations, Betelgeuses average surface temperature on February 14 was about 3,325 Celsius/6,017 Fahrenheit.

Thats only 50-100 Celsius cooler than calculated in 2004.

Orion rising behind the iconic Hoodoos on Highway 10 east of Drumheller, Alberta, near East Coulee, ... [+] on a moonless January night, with illumination by starlight and by a nearby yardlight providing some shadows and warmer illumination. Clouds are beginning to move in and are providing the natural star glows. (Photo by: Alan Dyer /VW PICS/Universal Images Group via Getty Images)

Orion rising behind the iconic Hoodoos on Highway 10 east of Drumheller, Alberta, near East Coulee, ... [+] on a moonless January night, with illumination by starlight and by a nearby yardlight providing some shadows and warmer illumination. Clouds are beginning to move in and are providing the natural star glows. (Photo by: Alan Dyer /VW PICS/Universal Images Group via Getty Images)

So, not much has changedand dimming should be ruled-out. A comparison with our 2004 spectrum showed immediately that the temperature hadnt changed significantly, said Massey. We knew the answer had to be dust. The theory is that newly formed dust is absorbing some of Betelgeuses light. The other possibility is that huge convection cells within Betelgeuse had drawn hot material up to its surface, where it had cooled before falling back into the interior. A simple way to tell between these possibilities is to determine the effective surface temperature of Betelgeuse, said Massey.

However, if youre hoping to see Betelgeuse go supernova and shine brightly day and night for weeks or months, keep looking. Red supergiants are very dynamic stars, said Levesque. The more we can learn about their normal behaviortemperature fluctuations, dust, convection cellsthe better we can understand them and recognize when something truly unique, like a supernova, might happen.

Wishing you clear skies and wide eyes.

Read this article:

Now Whats Going On With Betelgeuse? The Future Supernova Just Isnt That Cool, Say Astronomers - Forbes

The astronomer and broadcaster Heather Couper, who has died aged 70 after a short illness, helped, with her passion for the subject, to redefine the way her science was presented on television.

She made her name with two series in particular, The Planets (1985) and The Stars (1988), both on Channel 4. In these programmes, rather than presenting from a TV studio, Couper took viewers inside the observatories that shaped the subject she loved. Her scripts were often laced with tales of stargazers from the past, and this historical context, presented from a personal point of view, showed the process of the science, and humanised it.

Couper was a pioneer for women in science both on and off screen. In 1984 she was elected the first female president of the British Astronomical Association. In 1993 she became the first female professor of astronomy at Gresham College, London, a position that had been held only by men since its inception in 1597.

Her success with The Planets and The Stars led to her founding the television production company Pioneer Productions in 1988 with her lifelong collaborator, Nigel Henbest, and the director of The Stars, Stuart Carter. A year later the company produced The Neptune Encounter, a documentary about that years flypast of the eighth planet in the solar system by Nasas Voyager 2 spacecraft.

Couper wrote dozens of books, mostly with Henbest, including three popular titles for children: Black Holes (1996), Big Bang (1997), and Is Anybody Out There? (1998). Her recent publications include The Universe Explained: A Cosmic Q&A (2018) and the 2020 edition of Philips Stargazing Month-by-Month Guide to the Night Sky. The pair also wrote a monthly astronomy column for the Independent from 1987 until early this year.

Couper had been captivated by space from a young age. She was born in Wallasey, Cheshire, to Anita (nee Taylor), a historian, and George Couper, a pilot. The family eventually settled in west London. As a child, Heather would sit up at night staring into the sky. On one occasion, when she was aged around eight, she saw a green shooting star, but her parents did not believe that such a thing could exist. She was vindicated the next day by a newspaper story on the star, and resolved to be an astronomer.

Aged 16, she wrote to the astronomer and TV personality Patrick Moore asking if her gender was a barrier to a career in astronomy. She received a letter back from him saying that being a girl was no problem at all. However, on leaving St Marys girls grammar school in Northwood, Middlesex, Couper initially abandoned that aspiration to become a management trainee at Topshop.

After two years she realised that she was not suited to a career in retail, and in 1969 became a research assistant at Cambridge observatory, while taking maths A-level at night school. She became a fellow of the Royal Astronomical Society in 1970.

She then studied astronomy and physics at the University of Leicester, where she met Henbest. They became platonic companions for life, later (in 1985) forming the business partnership Hencoup Enterprises. Couper graduated in 1973 and began a PhD at Linacre College, Oxford. However, her drive to popularise her subject had taken hold, and she left after 18 months to begin giving talks at local societies and evening classes.

From 1977 onwards she gave regular lectures at the Old Royal Observatory at Greenwich, and in 1978 was invited to appear on Moores show The Sky at Night. This led to her presenting a childrens astronomy series, Heavens Above (1981), for Yorkshire TV.

Couper was also a skilled radio broadcaster. She presented the BBC World Services astronomy magazine programme Seeing Stars (1994-2000) and Britains Space Race (2007) on Radio 4. The following year, also for Radio 4, she wrote and narrated Cosmic Quest, a history of astronomy over 30 15-minute episodes.

I worked with Heather when we were both guest lecturers in China for the 2009 total solar eclipse. Her ability to captivate an audience from the moment she took the microphone was extraordinary.

She was a member of the Millennium Commission (the body responsible for the distribution of funds raised by the National Lottery) from its inception in 1993 until its disbandment in 2009. Coupers science background was unique among the commissioners and she became the subjects chief advocate, with science and environment centres around the UK, such as the National Space Centre in Leicester, benefiting. She was appointed CBE in 2007. In 1999 an asteroid, 3922 Heather, was named after her.

Beyond astronomy, Coupers interests were the countryside, church architecture and classical music. She and Henbest lived first in Greenwich, and then in the Chiltern Hills. He survives her.

Heather Anita Couper, astronomer, writer and broadcaster, born 2 June 1949; died 19 February 2020

Read more from the original source:

Heather Couper obituary - The Guardian

Now, it seems that every time scientists make a new discovery about Mars, the conversation quickly shifts to: When are we going to go there and see for ourselves? With the upcoming Mars 2020 mission, scientists are finally taking the first steps toward exploring the Red Planet in person.

Planned for launch between July 17 and August 5, Mars 2020 will embark on a roughly seven-month journey to the Red Planet, arriving February 18, 2021. And once engineers confirm its landed safe and sound, Mars 2020 will set to work achieving its four main objectives.

Theres plenty of overlap between Mars 2020s goals and those of previous rovers, but Mars 2020 still has a unique agenda. Namely, Mars 2020 will seek signs of past life by searching for sites that were once habitable; hunt for evidence of ancient microbes at those sites by studying rocks known to preserve life; collect and store rock cores for a future sample return mission; and help scientists prepare for the hurdles human explorers will face on Mars, partly by testing a method for pulling oxygen out of thin air.

But first, the newly named rover has to get to the Red Planet.

Original post:

The rover formally known as Mars 2020 - Astronomy Magazine

Orbit of asteroid (52768) 1998 OR2. It requires 3 years and 8 months to orbit the sun onc. It gets nearly as far from the sun as Jupiter (about 5 times Earths distance from the sun). Image via NASA/ JPL.

Have you heard the buzz about a big very big asteroid thatll pass close in April? We have! No, it wont hit our planet. In fact, it wont have any effects on Earth. Still, excitement is building among both professional and amateur astronomers about the upcoming flybyof asteroid (52768) 1998 OR2 the biggest asteroid due to fly by Earth this year coming closest on April 29, 2020. This space rock is probably at least a mile wide (1.8 km) and maybe 2 1/2 times that big (4.1 km). Closest approach is April 29 around 5:56 a.m. Eastern Daylight Time (09:56 UTC; translate UTC to your time). Professional observatories are already pointing their telescopes at the huge space rock. Amateur astronomers with smaller telescopes will have an opportunity to see it as a slow-moving star very soon; if thats you, we give charts and tips for observers at the bottom of this post that should help.

No access to a telescope? No problem. The Virtual Telescope Project in Rome will host a free, online public viewing of the asteroid on April 28, 2020.

Lets make absolutely clear that theres no chance of a collision between this asteroid and Earth. Asteroid (52768) 1998 OR2 will pass at some 4 million miles (6 million km), or about 16 times the Earth-moon distance. Its true the object is classified as a Potentially Hazardous Asteroid. The Center for Near Earth Objects defines such an object as one that comes as close to Earth as:

0.05 AU or less [about 19.5 lunar distances] and an absolute magnitude of 22.0 or less

In other words, such objects are reasonably close and reasonably big. And do we need to say there are a bunch of objects like this? Wikipedia lists 22 of the largest here. Recent decades have revealed more and more asteroids orbiting the sun, as the video below from NASAs Jet Propulsion Laboratory shows:

None of the 22 Potentially Hazardous Asteroids listed by Wikipedia is known to be on a collision course with Earth in the foreseeble future. In fact, none of the asteroids in the video above is known to be on a collision course. Likewise, asteroid (52768) 1998 OR2 isnt on a collision course with Earth, not anytime soon. The orbit of this asteroid is well known for at least the next 200 years. Its closest approach to Earth in this century and the next will happen in 2079, when itll swoop to within about a million miles of Earth (still about four times farther away than the moon). That 2079 sweep past Earth will still be a big deal. Asteroid (52768) 1998 OR2 is the largest known of all large Near-Earth Objects thatll pass less than five times the Earth-moon distance over the next two centuries!

Astronomers at Arecibo Observatory in Puerto Rico will study asteroid (52768) 1998 OR2 from April 8 to 24, 2020, as the space rock travels through space at19,461 miles per hour(31,320 km/h).

The high resolution radar images that will be obtained from Arecibo should provide scientists a better estimate of the space rocks size and shape.

Astronomers with reasonably sized telescopes are already capturing images of asteroid (52768) 1998 OR2. This March 6, 2020, image of the asteroid comes from a single 30-second exposure, remotely taken with Elena, a 17-inch robotic telescope. At the imaging time, (52768) 1998 OR2 was at about 22 million miles (36 million km) from Earth. At its closest in late April, itll be about 4 million miles (6.4 million km) away. Image via Gianluca Masi/ Virtual Telescope Project.

How to see asteroid (52768) 1998 OR2 with a small telescope

During its April 2020 pass, this asteroid will at no time be bright enough to view with the unaided eye. However, its estimated to reach a visual magnitude of around 10 to 11, which means observers with at least 6-inch or 8-inch telescopes (the number indicates the size of the primary mirror) will see the asteroid (very slowly) moving in front of the stars!

Sky enthusiasts can initially use a wide-angle (32mm or 35mm) eyepiece to point the telescope to a reference star in the asteroids path (charts below). After being assured that the instrument is pointing at the correct patch of the sky, a 26mm or 27mm eyepiece is recommended to detect the asteroids slow motion. You will want to note the star field, and watch for the object that moves over a period of about 10 to 15 minutes. Yes, thatll be the space rock.

This illustration shows the location of asteroid (52768) 1998 OR2 on the night of April 24, 2020 around 11:45 p.m. central time. As seen from central U.S., facing west, southwest. Illustration by Eddie Irizarry using Stellarium.

On April 24, 2020 at 11:45 p.m. central time, observers using small computerized telescopes can point their instruments at these reference stars, to observe asteroid (52768) 1998 OR2. Compare the views 10 or 15 minutes later to detect an apparent star that has changed position. Illustration by Eddie Irizarry using Stellarium.

There will be closer approaches of asteroids in the future, including Apophis, which although smaller will pass very close to Earth in 2029. Another, larger space rock 2 miles (3 km) wide designated as asteroid (415029) 2011 UL21 will pass slightly farther than (52768) 1998 OR2 in June 2024.

But the upcoming flyby in April 2020 of asteroid (52768) 1998 OR2 is the most significant close approach of an asteroid until 2027, as another huge asteroid known as (4953) 1990 MU will safely pass by Earth at 12 lunar distances.

Astronomers first discovered asteroid (52768) 1998 OR2 onJuly 24, 1998,from Haleakala Observatory, Hawaii.

Have a Go-To Telescope? Point your instrument at star HIP 48674 on April 25, 2020 at 10 p.m. central time to find the huge asteroid, which will appear as a slow-moving star. To see its movement, compare the views over about 10 to 15 minutes. Illustration by Eddie Irizarry using Stellarium.

Location of asteroid (52768) 1998 OR2 on the night of April 27, 2020. The space rock passes close to star HIP 50745 around 9:15 p.m. central time. Illustration by Eddie Irizarry using Stellarium.

Location of asteroid (52768) 1998 OR2 around the nights of closest approach (April 28-29, 2020). Facing south, as seen from the central U.S. Illustration by Eddie Irizarry using Stellarium.

Showtime! On April 29, 2020, around its closest approach to Earth, asteroid (52768) 1998 OR2 will pass close to galaxy NGC 3463 and star HIP 53416. Around 9:30 p.m. CT, point your small computerized telescope to these reference objects. Compare the views 10 to 15 minutes later to detect the apparent star that changed position. Thats the asteroid. Illustration by Eddie Irizarry using Stellarium.

On April 30, 2020 at 9:30 p.m. asteroid (52768) 1998 OR2 is located close to stars HIP 54875 and 55201. Use a GoTo telescope to locate these reference stars to be able to locate the slow moving asteroid. Illustration by Eddie Irizarry using Stellarium.

Bottom line: The huge asteroid known as (52768) 1998 OR2 will pass closest to Earth on April 29, 2020. Observers peering through telescopes will see it as a slow-moving star. Charts, tips plus how to watch online here.

See more here:

Heres how to see that huge asteroid thatll safely pass Earth in April - EarthSky

One people, one sky. That motto belongs to Astronomers Without Borders. Its founder and retired leader, Mike Simmons, recently brought a guest to Planetary Society headquarters. Olayinka Fagbemiro is with the Nigerian space agency and also heads Astronomers Without Borders in her nation. Emily Lakdawalla tells us about four exciting planetary science missions that are currently competing for selection by NASA. Bruce Betts tells us about the search for 100 earths even as he asks us to find a citizen of Middle Earth in space.

A Planetary Radio t-shirt from the Planetary Society store AND a Planetary Society r-r-r-rubber asteroid.

The winner will be revealed next week.

Which NASA Ranger mission imaged Mare Tranquillitatis, the Sea of Tranquility on the Moon?

Ranger 8 successfully imaged the Moons Sea of Tranquility in 1965 before being smashed to bitsintentionally.

Mat Kaplan: [00:00:00] Turning young African eyes toward the cosmos, this week on Planetary Radio.

Welcome. I'm Mat Kaplan of the Planetary Society, with more of the human adventure across our solar system and beyond. Mike Simmons stopped by the other day, the founder and just-retired leader of Astronomers Without Borders brought along a very special guest. He'll introduce us to Olayinka Fagbemiro of the Nigerian Space Agency. Olayinka is also National Coordinator for Astronomers Without Borders Nigeria. Together they'll tell us that the night's sky unites all of humanity.

Four new missions have made it to the next step in the long road toward selection by NASA. Emily Lakdawalla will introduce them to us. And Bruce Betts brings back his favorite game, Where in the Solar System, with a tip of the hobbits hat to Middle Earth. It's almost here. The new expanded [00:01:00] version of The Downlink will premiere on Friday, March 6th. You'll see it at planetory.org/downlink, which is also where you can be one of the first to sign up for the newsletter.

Here's a sampling of the space headlines Jason Davis collected for the most recent addition. The largest unnamed world in our solar neighborhood now has an official moniker. It's Gonggong, named after a Chinese water god. Gonggong may be a bit larger than Pluto's companion, Charon. The body's discoverers asked The Planetary Society to help with the public selection process. Gonggong won by a 2:1 margin, and the name has been accepted by the International Astronomical Union.

JPL engineers are making more aggressive attempts to get Insight Lander's probe, known as the mole, to get a grip. The instrument is still stuck at the surface of Mars. Now the spacecraft's scoop will press on the mole as it attempts to hammer itself. [00:02:00] Meanwhile, scientists has published results of the first 10 months of data from Insight's seismometer. It found 174 marsquakes. More than 20 of these had magnitudes of greater than three, which I can tell you, growing up in L.A., is enough to shake you up. More to come, no doubt.

The Juno mission has achieved one of its major goals by determining that water makes up about one quarter of 1% of Jupiter's atmosphere. That's three times as much as Galileo's atmospheric probe found when it plunged into the giant world back in 1995. Scientists have long suspected that the probe was simply unlucky enough to enter a- an unusually dry spot.

And NASA has acknowledged that the first liftoff of the Space Launch System, that giant rocket at the core of the agency's Artemis program, will be delayed to sometime in 2021. NASA still says it can return humans to the Moon's surface by [00:03:00] 2024.

Emily Lakdawalla is The Planetary Society's solar system specialist. Emily, great to get you back on to, uh, talk about these four brand-new Discovery program candidates. Could this be the year that Venus finally gets a little more love?

Emily Lakdawalla: It could be. I mean, Venus has been visited by a couple of missions, but by NASA for an awfully long time. In fact, it's so long ago, it was before I was even a graduate student. I was working on Magellan data for my grad program. And that's the last time NASA got any up-close and personal data. So I'm so excited to see two Venus misio- missions in this Discovery down selection, and I think the community is really, really hoping that- that one of them will get picked.

Mat Kaplan: All right. Remind us, first of all, where are these Discovery missions in- in the entire spectrum of NASA's, uh, planetary science missions.

Emily Lakdawalla: Well, Discovery is the lowest-cost program of NASA missions. There's three basic classes of NASA missions. There's Discovery, New Frontiers, and Flagship. [00:04:00] Discovery missions cost around $500 million. New Frontiers are about a billion. And then Flagship are like 2 billion and up. They're supposed to fly the most often. They're supposed to push the envelope, in one way or another, either with the type of instrument that they're using, a type of measurement they're trying to perform, the way they operate, the kind of, uh, propulsion they use, you know, one of those things. It's designed to be rapidly-developed missions that help NASA prove new technologies that they could later go on to use on some of their bigger missions.

Mat Kaplan: Insight on Mars is one of these, right?

Emily Lakdawalla: Insight is one of those. It's not the best example, actually, because, uh, of the way that that year's selection worked. But there have been some really spectacular missions that- that tested really new stuff. Like Dawn going to Ceres and Vesta. We had Messenger at Mercury, which was a fabulous mission. There's a huge number, uh, the Discovery program has really been quite successful over time. The hope is that they'll actually be able to pick two out of the four. They'll pick at least one, but people [00:05:00] really are pulling for two.

Mat Kaplan: And they did pick two in last round, right? Those two, uh, asteroid missions?

Emily Lakdawalla: That's right. There's Lucy and Psyche. Lucy is a mission that's going to explore a bunch of, um, centaurs and, uh, Trojans. These are rather distant small bodies. They tend to be ... They orbit around, uh, Jupiter's distance from the sun. And so it'd be the first kind of mission to go to multiple objects like that. And then Psyche's a really fun one. It goes to an all-metal asteroid. So those will be very cool. And I think, because both of those were asteroid missions, people were not surprised that the four mission down selected in this round, not one of them is proposed for an asteroid.

Mat Kaplan: I can't wait for, uh, the Psyche, in particular, 'cause it's gonna be so interesting to finally see one of those metal, uh, monsters up close. But take us through these, uh, four, uh, candidates that are, that are still competing in this round.

Emily Lakdawalla: Well, we'll talk about the Venus missions first, since, uh, since you mentioned those already. There's two. One's called DAVINCI+, um, the other one's called VERITAS. Both of them were [00:06:00] actually in the final round the last Discovery selection that wound up with two asteroid missions, which is one the reasons I think that people are really fairly sure that at least one of these will go forward. They're quite different missions. DAVINCI is- is one that will penetrate the atmosphere, is studying the- the qualities of the atmosphere on the way down. It's basically an atmospheric probe. It will take cameras, uh, as it's descending. But it's not designed to last a long time.

The VERITAS mission is a- a radar mission, which is, in a way, like Magellan, but it's specifically focused on topography, which I can tell you, as a person who studied Venus once, it is so necessary. The modern kinda renaissance of Mars exploration began with Mars Global Surveyor, which got the first really good topographic map of Mars, that formed the basis of all the rest of the Mars orbital work that's been done for the following 25 years. This mission stands a chance to do the same thing, to develop the topographic map that will the basis of everything we do on Venus for decades. So, [laughs], as you can probably, I'm a [00:07:00] little bit biased.

Mat Kaplan: [laughs].

Emily Lakdawalla: I love my Venus radar. I think topography's so necessary, and I've known Sue [Smecker 00:07:05], who's the, uh, principal investigator, for a long time, ever since I was a grad student. And I- I would dearly love to see her be in charge for a mission like this. She's lovely.

Mat Kaplan: Now, what about the other two? They're going much further out.

Emily Lakdawalla: Yeah. So the other two missions are pretty exciting. They're outer planets' missions, and uh, one of them has been proposed before, and that's Io Volcano Observer, which is exactly what it says on the tin. It's a spacecraft that's designed to orbit Jupiter and, um, observe the volcanos on Io. It's designed to try to figure out how, uh, all the massive tidal forces that are operating in- in orbit around Jupiter, between Jupiter tugging on Io, and- and Europa and Ganymede also, how that generates the heat that's coming out of Io's interior. Just how much heat is coming out of it, and try to understand better what the volcanism is doing on Jupiter's innermost and very volcanic moon.

Mat Kaplan: Can we assume that it would also have a- a camera onboard, so that we could get [00:08:00] really up close to those, uh, magnificent volcanos?

Emily Lakdawalla: It absolutely would. There's no question. As I've, as I've said before with Juno, it would be a crime to go to Jupiter and not have a camera onboard. This one, I'm sure, would have a- a nice, uh, infrared camera, near infrared, because Io's volcanos are so hot that you can map them, uh, by their heat alone. And so you would be studying at both in like regular visual images, and also in infrared wavelengths, where they'd be illuminated by their own heat. So you'd be able image them both in day and at night, to see the heat that's coming out of the volcanos.

Mat Kaplan: I would only add that it seems like a crime to go anywhere without a camera.

Emily Lakdawalla: [laughs].

Mat Kaplan: [laughs]. All right. How about this last one, the fourth, and- and the one that, uh, will be going the furthest, if it's funded?

Emily Lakdawalla: That's right. So Trident, uh, is a flyby of Triton, which is the largest moon of Neptune, the only actually big moon of Neptune, and likely a captured Kuiper Belt object. It's even larger than Pluto, and is otherwise very Pluto-like in its composition and characteristics. It also orbits [00:09:00] Neptune backwards, so it's probably a captured object. It probably didn't start out its existence there. We know that it has active geysers. Uh, it's just an opportunity to go by, map it, look for changes that have happened since Voyager 2 flew past, um, try to understand the particles and the environment around it.

And you know, Voyager 2, as cool as the flyby of the Neptune system was, it was a spacecraft that was really not designed to operate and get great pictures of things so far from the sun. So this would be the first really good flyby of Triton. Plus they'd also, obviously, get some good close-up views of Neptune. They'd fly past some small bodies along the way, probably, and do some great science, the way that New Horizons is doing science on small bodies in the outer solar system. And it has the distinction of being the only one in the list that doesn't have an acronym for it's name. [laughs].

Mat Kaplan: [laughs]. I don't know if it gets points for that or not. How soon might we be hearing the decision from NASA as to which of these, hopefully two of them at least, [00:10:00] uh, will be headed for space?

Emily Lakdawalla: Well, first the four teams are being given some time to do some further work to try to nail down the costs and the challenges involved in the mission. They can spend a little money, um, trying to develop some of the necessary technologies forward a little bit. And then they, uh, will give big reports to, uh, NASA about their progress. NASA will visit them and see how well-prepared they are to actually operate a mission. And then they'll make a down-selection in 2021.

I don't know exactly when it will be yet, and we don't know how many it will be yet. It will be at least one. Could be two. And um, [laughs], who knows? I guess, well, as long as we're being optimistic we can hope for three. Probably not gonna happen-

Mat Kaplan: [laughs].

Emily Lakdawalla: ... but uh, it would be nice.

Mat Kaplan: Well, we'll hope for quality and quantity-

Emily Lakdawalla: Thank you.

Mat Kaplan: ... in this round of, uh, the- the- the- the Discovery program. Oh, one more question. How soon after they are chosen might we actually see some of these head toward their destinations?

Emily Lakdawalla: Well, it doesn't take all that ... It shouldn't take all that long to develop a Discovery mission. Usually [00:11:00] it's, it's just, uh, somewhere around four or five years to launch. And then, of course, how long it takes to get data depends upon how long a cruise they have. It's very quick to get to Venus, so we could be, as you know, maybe five months after launch y- you'll be at Venus, and already set up and starting to acquire preliminary data.

But getting to other places, like orbiting Jupiter, and flying past, uh, Neptune, take a long time. When you do planetary science, especially if you're an outer planetary scientist, you need to be really patient, and be willing to accept the fact that you might be starting a project and launching, and then handing it over to a former graduate student to operate once it's in flight.

Mat Kaplan: Emily, I'm glad to still be playing the long game with you here in planetary science. Lots, uh, to look forward to, and I'm sure we'll talk again soon. Thanks very much.

Emily Lakdawalla: You're welcome, Mat.

Mat Kaplan: That's our solar system specialist, Emily Lakdawalla, of The Planetary Society.

Mike Simmons discovered our universal fascination with the sky when he started sharing astronomical wonders decades ago. It [00:12:00] led him to found Astronomers Without Borders, or AWB, where their motto is, One People, One Sky. There's hardly a portion of our planet that Mike has not visited, encouraging scientific wonder and curiosity wherever he goes.

Olayinka Fagbemiro is a kindred spirit. She is Assistant Chief Scientific Officer for Planning, Policy and Research at the National Space Research and Development Agency in Nigeria. She also leads the agency's space education outreach unit, so it's easy to see why Olayinka would also embrace the AWB mission. She's had remarkable success as AWB's national coordinator in Nigeria. In addition, she serves as the public relations and education officer for the African Astronomical Society.

Mike called the other day to ask if he could bring Olayinka to The Planetary Society's Pasadena headquarters, as she continued an [00:13:00] astronomy-focused tour of California and the United States. We were thrilled to oblige, especially because I couldn't wait to share Mike and Olayinka's stories with you.

Mike Simmons, always a pleasure to talk to you on Planetary Radio, and it is great to see you here. You've never been to, uh, this headquarters for The Planetary Society before.

Mike Simmons: No, this is the first time in this particular building. I was at the original one, which is a great old Pasadena house.

Mat Kaplan: I miss it.

Mike Simmons: [laughs]. Yeah. And the other one, uh, short-term. This is the first time I've stopped by here.

Mat Kaplan: Well, I'm glad you made it, and I'm especially glad, because you brought the special guest who is sitting next to you right now. Would you please introduce her?

Mike Simmons: Well, this is Olayinka Fagbemiro, from Nigeria. And Olayinka, uh, works for the space agency there. But of more interest to me is that she created and runs, uh, Astronomers Without Borders Nigeria, does fantastic things in the country to introduce astronomy and science to some very special [00:14:00] people. So, uh, it- it's wonderful to have her here visiting us for the first time.

Mat Kaplan: I suspect that most of our audience will know that you were Astronomers Without Borders for many years. You founded the organization.

Mike Simmons: Yes.

Mat Kaplan: And you've moved on. You're doing other exciting now. Obviously, that had to do with why you crossed paths. But how did you end up meeting each other and- and get to know each other?

Mike Simmons: Olayinka reminded me just the other day that, actually, we met at a conference. And I meet a lot of people. I hear from people in other countries all the time. And I always write back, because you never know. She was somebody who went back, inspired by the idea, and created something really incredible. And it's great to be able to do that as a part of Astronomers Without Borders. But really, people are doing outreach and education in astronomy, in STEM fields, all around the world. And to be able to give somebody, uh, uh, some inspiration to do it as a part of the network of people around the world is- is [00:15:00] fantastic.

Mat Kaplan: Olayinka, welcome to The Planetary Society. I ... It looked like you enjoyed the tour.

Olayinka Fagbemiro: Yes, thank you so much. Um, it's a pleasure being here. And I'm particularly, um, excited to be at this place. I love the tour that- that you have, an amazing space, and I'm glad to be here. Thank you.

Mat Kaplan: We like it very much, and I- I'm glad that you've had a good time as we showed you around.

Olayinka Fagbemiro: Yeah.

Mat Kaplan: You got a- a nice, uh, introduction to LightSail from Bruce Betts, our Chief Scientist.

Olayinka Fagbemiro: Yeah, yeah. It's really great, because that's, um, the first time, uh, hearing about this particular project, and I think it's amazing. I would let it go back home and share with my network and- and see what more we can learn and inspire little kids about- about that. I think it would be a great, um, topic to discuss.

Mat Kaplan: [French 00:15:50]. We hope so, anyway. I- I certainly agree with you. It was only two or three days ago that Mike let me know that you were in town, and he wondered if you'd be [00:16:00] able to stop by. And of course, we love visitors. I was intrigued immediately, because he talked about your role with Astronomers Without Borders in Nigeria, but he also said that you have a day job. You work with ... Is it the N-?

Olayinka Fagbemiro: The Nigerian Space Agency?

Mat Kaplan: Yes, yeah.

Olayinka Fagbemiro: Yes, yes. Yeah.

Mat Kaplan: Tell me about that.

Olayinka Fagbemiro: When I left university in the year 2004, I started a job with the Nigerian Space Agency in the year 2007, as an outreach and an education officer for- for space education. I've been there ever since. And along the line I- I got involved some other projects, and um, and Astronomers Without Border, like, um, universe awareness. And it's been awesome, like having a day job, and then having the time to do this other very important work. I- I think it's, it's a great thing for me, because I get, eh, the chance to inspire little ones. We're trying to raise the [00:17:00] next generation of space scientists, and- and- and STEM guys in Africa.

Also, I'm the Public and, um, Education Officer for Ash- ... African Astronomical society. What I do in Nigeria, I- I do by extension across Africa, African Astronomical Society is, um, an organization with a very big, um, reach to African countries. I think about 40 plus-

Mat Kaplan: Hmm.

Olayinka Fagbemiro: ... African countries are- are- are part of AfAS. One of the major things we're trying to do is first create awareness about astronomy across Africa. Astronomy is not really so much developed in Africa as it is in- in the, in the US and, or Europe. So one of the major work we're trying to do is to create the awareness, get many young people involved in astronomy. We're trying to see [00:18:00] a way of getting more people in the career part of astronomy, and also to use astronomy as a means of teaching STEM, science, technology, engineering and mathematics-

Mat Kaplan: Mm-hmm [affirmative].

Olayinka Fagbemiro: ... across Africa. These are some of the many things that we do as- as AfAS.

Mat Kaplan: My guess is that your day job with the Nigerian space agency probably keeps you pretty busy are- are they happy to have you involved with all these other activities like AWB?

Olayinka Fagbemiro: Yes, they- they- they are. And, um, I think, uh, I've got a very good support in the Nigerian space agency because Nigeria has a pretty big country with a population of almost 200 million people and young people are most 30% to 40% of this population. So this space agency is happy to have as many extra hands as possible in reaching out to- to this large population of young [00:19:00] people. And because my role in the Nigerian Space Agency, it's pretty much like an extension of what I do with AWB, Space Education Outreach.

Mat Kaplan: Mm-hmm [affirmative].

Olayinka Fagbemiro: I personally had the Space Education Outreach of the agency and also we have this new space museum. We have a lot of young kids coming around almost on daily basis, which I- i coordinate as well. So it's, it's almost like there are no demarcations between what I do as- as Nigerian Space Agency and what I do as AWB.

Mat Kaplan: That's great. Is that space museum, is that the one you showed us the video of a little bit that was in a refugee camp or is that separate?

Olayinka Fagbemiro: No, that- that was, um, a project of AWB. It- it was a project about having an astronomy hub for kids in the internally displaced peoples camp. Uh, so in Nigeria because of the problem of [00:20:00] the insurgency that we, we've got going on, uh, around the Northern part of Nigeria.

Mat Kaplan: Boko Haram?

Olayinka Fagbemiro: Boko Haram, yes. So we have a lot of displaced people from across the region, uh, affected by- by the insurgency. So we have of course people with young children in these camps. A few years back we thought these kids should also have a feel of what space and astronomy and all those funs could be. So we- we- we- we started a project of establishing an astronomy hub for- for these IDP guys. And, um, with the support of Office of Astronomy for Development Cape town, we were able to have the first one, which was a project that was targeted at this young kids who are mostly out of school.

And then we also had to bring in some counselors because we- we needed them [00:21:00] to become ... many of these guys are traumatized. Many of them were-

Mat Kaplan: Of course.

Olayinka Fagbemiro: ... displaced from their homes. Many of them have one or both parents killed due to the insurgency. And so they are basically not in the right frame of mind to- to even learn. So we had to bring in some- some counselors and- and we went ahead and made this, um, solar powered astronomy hub, which has smart TVs and internet connectivity with a lot of materials and- and videos and, um-

Mat Kaplan: It's beautiful little facility-

Olayinka Fagbemiro: Yeah, it is.

Mat Kaplan: ... from what I could see in the video.

Olayinka Fagbemiro: Yeah, it is. It is small, but it's also very effective because we have some people managing the project and what we do is, because we have a lot of kids in this camp, we- we have almost 300, um, young- young people. So we, we've been able to [00:22:00] look for a way to make all of them at least once in a week have access to this hub.

Mat Kaplan: Mm-hmm [affirmative].

Olayinka Fagbemiro: Yeah, so we have like a timetable of, okay, so you're go in maybe every Wednesday or every Monday and- and use the computer, use the smart TV, you know, just have fun. We have a lot of posters on astronomy and it's been cool.

Mat Kaplan: I'll be back in moments with Olayinka Fagbemiro, the middle of Astronomers Without Borders. Nigeria and AWB founder, Mike Simmons.

Speaker 5: Hi, I'm Yale astronomer, Debra Fischer. I've spent the last 20 years of my professional life searching for other worlds. Now I've taken on the 100 Earth's project. We want to discover 100 earth-sized exoplanets circling nearby stars. It won't be easy. With your help, the Planetary Society will fund a key component of an exquisitely precise spectrometer. You can learn more and join the search a planetary.org/100earths. Thanks.

Mat Kaplan: [00:23:00] Welcome back to Planetary Radio. How many children are among the displaced in- in Nigeria? Do you, do you know roughly?

Olayinka Fagbemiro: Maybe not the displaced, but- but the latest, um, UNICEF statistics says they're 13.2 million out of school kids in Nigeria.

Mat Kaplan: Wow, out of school?

Olayinka Fagbemiro: Yes.

Link:

Astronomers Without Borders - The Planetary Society

See the faint concentration of light toward the center of this image? Thats the elusive gegenschein aka the counterglow a diffuse spot visible in the darkest of skies, centered at the point directly opposite the sun. Sunlight reflecting on interplanetary dust causes it. Image via Project Nightflight.

Article and most photos by Erwin Matys and Karoline Mrazek of Project Nightflight, whose mission is to promote the conservation of the starry sky as environmental resource.

The suns counterglow or gegenschein is kind of a stargazers legend. Every amateur astronomer has heard about it, only a few of them have actually seen it, and even fewer were lucky enough to capture an image of this dim and ghostlike apparition. As a fellow observer put it:

The gegenschein is certainly not a GoTo object.

Matter of fact, it isnt an object at all. But lets start from the beginning.

What exactly is the gegenschein?

It is widely known that the space between the planets isnt empty. The plane of the solar system is filled with an enormous disk of small dust particles with sizes ranging from less than 1/1000 millimeter up to 1 millimeter. It is less commonly known that this interplanetary dust cloud is a highly dynamic structure. In contrast to conventional wisdom, it is not an aeon-old leftover from the solar systems formation. That primordial dust is long gone. Todays interplanetary dust is in an astronomical sense of speaking very young, only millions of years old. Most of the particles originate from quite recent incidents, like asteroid collisions.

This is not the gegenschein. The picture shows the zodiacal light, which is closely related to the gegenschein. Here imaged from a rural site, the zodiacal light is a cone of light extending from the sun along the ecliptic, visible after dusk and before dawn. The gegenschein stems from the same dust cloud, but is always opposite the sun, for example, highest in the sky at midnight. The gegenschein is much harder to detect or photograph than the zodiacal light. Image via Project Nightflight.

Exposed to various forces, the particles do not remain in stationary orbits but inhabit the disk in ever-changing motion. The smallest particles (less than 1/1000 millimeter) are swiftly blown out of the solar system by the solar wind. The larger particles dont survive very long either. They tend to collide with larger bodies or slowly spiral into the inner solar system where they fall into the sun.

Nevertheless, the supply of interplanetary dust particles is constantly replenished by the above-mentioned asteroid collisions and the erosion of comets. So, the interplanetary dust cloud of the solar system is not a static formation but a dynamic structure consisting of quite young components.

For an observer on Earth, this dynamic dust cloud is mainly visible in the form of the zodiacal light. After dusk and before dawn it extends as a cone of light from the sun along the ecliptic path. Often called the false dawn, the zodiacal light is quite bright and can be seen from any observing site that doesnt suffer from severe light pollution, especially when the ecliptic is high in the sky. For Northern Hemisphere observers, this is the case in the evening sky during spring and in the morning sky during autumn.

The morning and evening zodiacal light are the two areas of the interplanetary dust disk where sunlight gets forward scattered to earth, resulting in the bright silvery light cones. The interplanetary dust disk is also visible along the rest of the ecliptic path, where it is called the zodiacal band. Unlike the zodiacal light, however, these sections are very hard to detect since they have an extremely low surface brightness. But at the point directly opposite the sun the geometry again works in our favor and enhances the visibility of the interplanetary dust. This is the area of the gegenschein.

But why does the gegenschein glow brighter than the rest of the zodiacal band? Looking at the interplanetary dust disk from Earth, the section at the antisolar point is illuminated from directly behind our heads. This results in an increase in brightness that is called the opposition effect. The opposition effect is a frequent phenomenon for solar system bodies. For example, the moon shows a significant peak in brightness around full moon, i.e. at its opposition. Another example are Saturns rings in the days around opposition, when they brighten drastically.

The main reason for this brightening during opposition is shadow hiding, meaning that all particles are fully illuminated. This opposition effect can even be experienced here on Earth during daylight if you are outdoors and look at the ground in front of you. If the ground is sufficiently coarse, you will see a brightening around the shadow of your head. To document this phenomenon, we made the photo below, which shows the opposition effect on volcanic gravel.

This is like the gegenschein. For this photo, a small action cam was positioned on a tripod looking down on volcanic gravel on La Palma island. The insert shows some of the gravels with a size of several millimeters and their rough surface structure. Around the cameras shadow the opposition effect results in an obvious brightening. The glow pictured here is similar to the glow of the gegenschein on the night sky. Image via Project Nightflight.

Interestingly, the brightening around the cameras shadow had an apparent diameter of 10 degrees, which is about the same size as the diameter of the gegenschein in the night sky. Next time you walk on a rough surface in sunlight, give it a try and look for this terrestrial version of the counterglow.

To sum it up, the gegenschein is not an object. It is a play of light on the solar systems interplanetary dust disk. The section of the dust at the antisolar point is squarely illuminated, which results in a brightness enhancement due to shadow hiding. This so-called opposition effect can be encountered at many occasions, but with the gegenschein it makes its most ghostlike and outlandish appearance. This is probably the reason why it is such a prized trophy among amateur astronomers.

How we captured the gegenschein

From our observing and photography sessions at dark-sky sites, the gegenschein was a familiar companion. Out under the stars, sooner or later one of us would mention: Mmh, the gegenschein is quite obvious tonight, followed by the typical reply: Yep, bright and shiny! This short dialogue would indicate that our eyes had reached full dark adaptation and our night vision was at maximum capacity. We often talked about making an image of our good old dark-sky companion, the gegenschein. But for some reason it never came to it. Other projects were in the way, on other occasions the position in the sky was not right, or the atmospheres transparency was just not good enough.

But on the night from October 30 to 31, 2019, we finally did give it a go. On October 30 we were already several days on an imaging excursion on La Palma island. During daytime the annoying Calima weather pattern had finally stopped and skies were again as deep blue and transparent as they can be on this beautiful stars island. Accommodated in a solitary finca far away from inhabited areas and about 800 meters (2,600 feet) above sea level we had the perfect conditions for photographing the gegenschein. Around midnight, when the counterglow culminates, our instruments registered a sky brightness of 21.4 magnitudes per square arcsecond in the zenith. This is so dark that Sirius noticeably brightened the landscape when it rose behind a mountain ridge later that night. The gegenschein itself was pretty obvious to the unaided eye. Below the constellation Aries, directly on the ecliptic path, a distinct glow about 10 degrees across marked the antisolar point. The very faint zodiacal band crossing the whole sky was visible too, almost looking like an artificial marking of the ecliptic. Under these conditions, shooting the gegenschein was an easy task.

For those interested in the technical details: we made 23 unfiltered exposures of 4 minutes with a 16mm lens @f/5.6 on a Baader-modified 1100D Canon DSLR. For sky tracking we used a purely mechanical device, the Mini Track LX2. This innovative device is a frequent companion on our imaging excursions. For those interested in more details, we provide a thorough review of the Mini Track LX2 for download on our website. The total weight of our imaging gear was less than 3 kilograms (6.6 pounds), including camera and tripod. The 23 individual exposures of the gegenschein were later calibrated, registered and stacked with DeepSkyStacker. Processing of the final image was done in Photoshop, where we applied substantial contrast enhancement.

How you can see the gegenschein

If you never encountered the gegenschein yourself, dont expect it to be as prominent as in the photograph at the top of this post. We applied heavy contrast enhancement to the image to make the counterglow, its shape, and its size better visible. To our human eyes, even under the best conditions the gegenschein is an elusive and dim glow. On several occasions we compared the visual brightness of the counterglow and sections of the Milky Way. We always found it to be about as bright as the dimmest parts of the winter Milky Way. The stretch of the Milky Way that approximates the counterglows brightness best is the section between the star Mirfak and the asterism called the Kids next to Capella. That is, very dim. Any bright object in its vicinity (e.g. Jupiter or Mars at opposition) makes it hard to observe.

Aside from being slightly brighter in the middle and fading out uniformly in all directions the gegenschein shows no structure at all. It has a roundish form, circular or elliptical, measuring approximately 10 degrees across. That is about the size of a fist stretched out at arms length.

Drawing of the gegenschein as seen on November 23, 2019, from a dark-sky observing site in Lower Austria. On this night the antisolar point was between the 2 star clusters of the Hyades and Pleiades. The drawing gives a realistic impression of what to expect when looking for the counterglow. Image via Project Nightflight.

If you want to hunt down the elusive gegenschein yourself, the tips below might come handy:

First of all, check the position: Before you begin searching for the gegenschein in the night sky you should check its current position. The map below helps you to determine where to look for it. It also shows you whether the counterglow is detectable at all, because its visibility highly depends on its position against the starry background. In June, July and December it is completely invisible, because it is in front of the Milky Way. Other obstacles can be the bright planets Mars and Jupiter. When one of them is near opposition, it is in the same region of the sky as the counterglow and may outshine it. Some planetarium programs or stargazing apps might also be useful tools to determine the position of the gegenschein. If the software provides an option to display the center of the earths shadow this will show you the current antisolar point.

View larger. | This map gives you an idea where to look for the gegenschein in front of the starry background. The scale at the bottom indicates the constellations that culminate at your local midnight on a given date. This also approximates where you can find the gegenschein on the dotted line of the ecliptic. For example, at the end of March it will glow in the constellation Virgo. Image via Project Nightflight.

Look for it at maximum height above the horizon: The gegenschein is always highest above the horizon around local midnight, so that is the best time of the night to give an observation a try. There should also be no moon above the horizon. But thats not all. Like the sun itself, the antisolar point too has different culmination heights during the course of the year. For observers in the Northern Hemisphere the antisolar point has its highest culmination at the winter solstice around December 21. Sadly, during December the gegenschein is in front of the Winter Milky Way and therefore invisible. So, the best months to see the gegenschein from northern latitudes are November and January. For Southern Hemisphere observers, the largest culmination height of the antisolar point happens at summer solstice around June 21. For southerners too, the Milky Way is in the way. Again, one should look before or after the solstice, in this case during May or August.

View larger. | Only if all of the conditions listed in this diagram are true, you have a valid chance of actually detecting the gegenschein. Image via Project Nightflight.

Try from the best observing location you have access to: The gegenschein cannot be seen from light-polluted sites. Even moderate light pollution diminishes the counterglows contrast way too much. Based on our observations, the absolute minimum to detect the gegenschein is a sky brightness of 21.0 mag/arcsecond2 in the zenith. But this applies only if you are already quite familiar with the gegenschein and know exactly what and where to look for. For first-time observers we recommend a site with a sky brightness of 21.2 mag/arcsecond2 in the zenith or better. These conditions can only be found far away from cities or other inhabited areas. Observing sites in the mountains especially qualify because of the reduced air mass at higher altitudes above sea level.

Wait for favorable weather conditions: Even if you observe from a dark-sky location, the average clear sky might not be good enough for seeing the gegenschein. What you really want is a night sky with exceptionally high transparency. This will only be the case if the air mass above your observing site is as dry as possible. To get an idea of the current situation at your location, you can use a website that provides weather forecasts for astronomical observations (e.g. 7timer.info). Sites like this display data about humidity at all tropospheric layers. Another condition for high transparency would be that the air is clean, i.e. free of dust. At mid-latitudes, the necessary conditions of dry and clean air often can be found after the passage of a cold front or a trough.

Expand your observing skills: Given you have good eyesight in the dark and you already have some observing experience, there are several observing techniques you need to master for the gegenschein. First of all, you need to learn how to become truly dark adapted. This might put your patience to a test, since your eyes need at least 3/4 of an hour to fully adjust to the dark. So, no smartphones or other handheld devices during this time. You should only use very dim red lights if you dont want to ruin your night vision. A second technique you might need for seeing the gegenschein is averted vision. With averted vision, you do not look directly at an object but a little off to the side, while continuing to concentrate on the object. This way you are using peripheral vision which is more sensitive to low light levels than the center of the eye. Some observers report that this technique makes a big difference for them and it might help you too. In any case, hunting down the gegenschein will improve your observing skills a lot. Besides, it makes a highly interesting project and sooner or later you too will be able to put that prized stargazers trophy on your shelf.

About Project Nightflight: Our mission is the starry sky. We internationally promote the conservation of the starry sky as environmental resource.To support this goal, we work together closely with our sponsors and international news media. We provide news portals, nature related websites, books, magazines and newspapers with high resolution images of the unspoiled night sky, catching stories about the magic of the starry sky, useful tips for stargazing and astrophotography and informative articles on light pollution prevention. With our images and stories, which are frequently published by major print and online news media, we raise awareness for the need to keep light pollution at bay. Our team is based in Vienna, Austria, and consists of experienced, world-wide active astrophotographers who work on a volunteer basis. Most of our active members are marketing or communication professionals. If you want to learn more about our organization please download the Project Nightflight profile.

Bottom line: The gegenschein isnt an object. Its a play of light on the solar systems interplanetary dust disk. The gegenschein lies at the antisolar point, the point exactly opposite the sun. At this point, sunlight squarely illuminates the dust that moves between the planets. In this way, the gegenschein is related to the zodiacal light, which also stems from sunlight reflecting from dust between the planets. But the gegenschein is much more elusive than the zodiacal light. Its a diffuse patch in the night sky, which moves directly opposite the sun.

Via Project Nightflight

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What is the gegenschein? | Astronomy Essentials - EarthSky

Finding new planets lurking in space isnt as hard as it used to be, but that doesnt mean its not a challenge. High-tech instruments like NASAs Kepler Space Telescope have provided researchers with a wealth of data that can be mined for new discoveries. University of British Columbia student Michelle Kunimoto did just that and now has 17 brand new planets to her name.

Kunimoto, a PhD candidate, is the lead author of a new paper published in The Astronomical Journal that describes the 17 new planets in rough detail. We dont know much about them, but at least one of them is approximately Earth-sized and is thought to be rocky, just like our own planet.

Many of the 17 planets are quite large and are thought to be mostly gas. There are lots and lots of gas planets out there, but finding smaller, rocky worlds has proven more difficult for astronomers. The planet now labeled KIC-7340288 b is around 50 percent larger than Earth and it happens to be in the so-called Goldilocks zone of its star, meaning that it may be warm enough on its surface to support liquid water.

This planet is about a thousand light years away, so were not getting there anytime soon! Kunimoto said in a statement. But this is a really exciting find since there have only been 15 small, confirmed planets in the Habitable Zone found in Kepler data so far.

The discoveries were made using a technique that has become popular amongst exoplanet hunters in which the light of a star is observed closely for changes in brightness. When a stars brightness temporarily fades, it indicates something passing in front of the star, from Earths perspective. These passes, called transits, can tell astronomers a surprising amount about the objects orbiting a star.

Details such as how long it takes the planet to complete an orbit and how much light it blocks as it passes in front of the star offer clues to its size and orbit. Astronomers can make a few assumptions based on that data and paint a clearer picture of what is lurking out in the cosmos.

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Astronomy student discovers 17 new planets - New York Post

A black hole about 390 million light-years away has caused the biggest eruption ever seen in the universe.

The supermassive black hole sits at the center of a galaxy located in the Ophiuchus galaxy cluster. Its eruption was about five times greater than the last record-holder.

Black holes suck up matter that comes close to them, but they often expel matter as well. When matter falls toward the black hole, itssometimes redirected into beams or jets that blast into space and slam into surrounding material.

Suspicions of an explosion arose in 2016 when NASAs Chandra X-ray Observatory reported evidence there was an unusual curved edge in the Ophiuchus cluster. Scientists thought such a structure could be carved out by the jets from the supermassive black hole, but only if there was a massive explosion of unprecedented magnitude. And the 2016 study couldnt confirm whether that was the case.

But then followed the radio evidence: A new team of scientists looked at the cluster with radio telescopes and their data showed the same curved edge. Based on their observations, the edge is the boundary of a cavity in the hot gas filling the cluster, which could only have been cleared out by an intense blast from a supermassive black hole.

The radio data fit inside the X-rays like a hand in a glove, Maxim Markevitch, a co-author of the paper, said in a NASA press release. This is the clincher that tells us an eruption of unprecedented size occurred here.

Ultimately, the discovery used data from a number of instruments including Chandra, the European Space Agencys X-ray observatory, XMM-Newton, the Murchison Widefield Array in Australia, and the Giant Metrewave Radio Telescope in India.

The eruption is no longer going on, according to the researchers, as the radio data dont show any evidence of current jets, which most likely ran out of fuel for growth. A paper with the findings was published February 27 in the Astrophysical Journal.

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Astronomers spot the universe's biggest known explosion - Astronomy Magazine