Category Archives: Astronomy

A new study uses Bayesian statistics to weigh the likelihood of life and intelligence beyond our solar system. Credit: Amanda Carden

New study uses Bayesian statistics to shed light on how extraterrestrial life might evolve beyond our planet.

Humans have been wondering whether we alone in the universe since antiquity.

We know from the geological record that life started relatively quickly, as soon our planets environment was stable enough to support it. We also know that the first multicellular organism, which eventually produced todays technological civilization, took far longer to evolve, approximately 4 billion years.

But despite knowing when life first appeared on Earth, scientists still do not understand how life occurred, which has important implications for the likelihood of finding life elsewhere in the universe.

In a new paper published in the Proceeding of the National Academy of Sciences today, David Kipping, an assistant professor in Columbias Department of Astronomy, shows how an analysis using a statistical technique called Bayesian inference could shed light on how complex extraterrestrial life might evolve in alien worlds.

The rapid emergence of life and the late evolution of humanity, in the context of the timeline of evolution, are certainly suggestive, Kipping said. But in this study its possible to actually quantify what the facts tell us.

To conduct his analysis, Kipping used the chronology of the earliest evidence for life and the evolution of humanity. He asked how often we would expect life and intelligence to re-emerge if Earths history were to repeat, re-running the clock over and over again.

He framed the problem in terms of four possible answers: Life is common and often develops intelligence, life is rare but often develops intelligence, life is common and rarely develops intelligence and, finally, life is rare and rarely develops intelligence.

This method of Bayesian statistical inferenceused to update the probability for a hypothesis as evidence or information becomes availablestates prior beliefs about the system being modeled, which are then combined with data to cast probabilities of outcomes.

The technique is akin to betting odds, Kipping said. It encourages the repeated testing of new evidence against your position, in essence a positive feedback loop of refining your estimates of likelihood of an event.

From these four hypotheses, Kipping used Bayesian mathematical formulas to weigh the models against one another. In Bayesian inference, prior probability distributions always need to be selected, Kipping said. But a key result here is that when one compares the rare-life versus common-life scenarios, the common-life scenario is always at least nine times more likely than the rare one.

The analysis is based on evidence that life emerged within 300 million years of the formation of the Earths oceans as found in carbon-13-depleted zircon deposits, a very fast start in the context of Earths lifetime. Kipping emphasizes that the ratio is at least 9:1 or higher, depending on the true value of how often intelligence develops.

Kippings conclusion is that if planets with similar conditions and evolutionary time lines to Earth are common, then the analysis suggests that life should have little problem spontaneously emerging on other planets. And what are the odds that these extraterrestrial lives could be complex, differentiated and intelligent? Here, Kippings inquiry is less assured, finding just 3:2 odds in favor of intelligent life.

This result stems from humanitys relatively late appearance in Earths habitable window, suggesting that its development was neither an easy nor ensured process. If we played Earths history again, the emergence of intelligence is actually somewhat unlikely, he said.

Kipping points out that the odds in the study arent overwhelming, being quite close to 50:50, and the findings should be treated as no more than a gentle nudge toward a hypothesis.

The analysis cant provide certainties or guarantees, only statistical probabilities based on what happened here on Earth, Kipping said. Yet encouragingly, the case for a universe teeming with life emerges as the favored bet. The search for intelligent life in worlds beyond Earth should be by no means discouraged.

Reference: An objective Bayesian analysis of lifes early start and our late arrival by David Kipping, 18 May 2020, Proceedings of the National Academy of Sciences.DOI: 10.1073/pnas.1921655117

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Columbia Astronomer Estimates the Odds of Extraterrestrial Life and Intelligence Emerging in Alien Worlds - SciTechDaily

This story appeared in the June 2020 issue as "A Universe of Galaxies."Subscribeto Discover magazine for more stories like this.

On the evening of Oct. 4, 1923, near Los Angeles, a young astronomer got into his car and began a motorized trek up to Mount Wilson. There, he arrived at the observatory that housed the 100-inch Hooker Telescope, at the time the largest telescope in the world.

Edwin Hubble was a fourth-year astronomer at Mount Wilson; he enjoyed using the Hooker Telescope because he was interested in, among other things, studying spiral nebulae. These mysterious gas clouds were scattered across the sky, and no one understood their nature. In the early days of the 1920s, Hubble had assigned himself the task of figuring them out.

He pointed the great telescope toward his favorite object: the nebula in Andromeda, M31. This spiral-shaped cloud is faintly visible to the naked eye under a clear, moonless sky. He then captured its image on a photographic plate. Hubble was excited by the result. On it, he found a suspected nova, an exploding star. The next night, he photographed M31 again, hoping to catch the nova and record it under better atmospheric stability. The second plate did indeed record the nova, but little did he know, he also had captured a plate that would become legendary in the history of science.

Astronomer Edwin Hubble made an exposure of the Andromeda Nebula with the Hooker Telescope at Mount Wilson Observatory near Los Angeles on Oct. 5, 1923. He was initially excited, believing he had recorded a nova, an exploding star. He marked the star, which lies between two tick marks he drew at the top right on the plate, with the letter N. The star turned out to be a Cepheid variable, and Hubble used it to prove that the distance to the Andromeda Galaxy was far greater than astronomers thought. (Credit: Courtesy of the Carnegie Observatories/Cindy Hunt)

His observing time over, he returned to his office to analyze the catch. Suddenly, Hubble made an astonishing realization: The nova was not a nova at all, but a particular type of star that changed its brightness, a Cepheid variable. Checking earlier plates, he was able to confirm that, and he realized that the stars faintness had incredible implications.

The star, and the nebula that encompassed it, must lie at a distance of a million light-years three times larger than anyone at the time believed the size of the whole universe to be. Today, thanks to improved measurements, astronomers know the object is 2.5 million light-years away.

Aided in part by earlier work done by Vesto M. Slipher and by his own colleague, Milton Humason, Hubble had at once discovered that the universe was far larger than anyone had believed, and that spiral nebulae like Andromeda were actually distant galaxies. They were whole systems of stars and gas, separated from our own Milky Way by a long hike.

At Arizonas Lowell Observatory, as early as 1912, Slipher had recorded the apparent velocities of spiral nebulae and, with the work now done by Hubble, it was clear the universe was expanding the galaxies were flying apart from one another over time. The universe was not only far larger than anyone had previously believed, but it was growing as time went on.

NGC 4565 in Coma Berenices is the brightest and most prominent galaxy in our sky that is oriented perfectly edge-on to our line of sight. We see its disk as a thin, silvery needle. Some 57 million light-years off, it lies in the Virgo Cluster and has a prominent central bulge, suggesting it may be a barred spiral. (Credit: Adam Block)

By 1929, astronomers had put a cosmic picture of the past together. If you traced the histories of many of the galaxies backward in time, it meant that the cosmos began with a small, infinitely dense point at its origin. This research was an extension of work originally done by Belgian astronomer Georges Lematre. Astronomers understood this cosmic point of origin, later called the Big Bang, as the start of the universe, and, they calculated, it must have occurred billions of years ago. The Big Bang had commenced the expansion that was driving all the galaxies away from each other as time rolls on. The whole universe seemed to be flying apart.

In the 1930s, Hubble began to study and classify galaxies into their various so-called morphological types, the array of structures astronomers saw in photographs. He eventually assembled the types of galaxies he observed into a tuning fork-shaped diagram. It contained spiral galaxies, barred spiral galaxies spirals containing a linear bar of material passing through their centers lenticular (lens-shaped) galaxies, and elliptical galaxies. He also identified irregular galaxies, clouds of stars and gas that lacked an organized shape. Later on, astronomers would identify peculiar galaxies, systems that appeared to be wracked with explosive or disruptive events. They also identified a class of galaxies called dwarf spheroidals, which seemed to be numerous in the local universe.

By the 1950s, French astronomer Grard de Vaucouleurs of the University of Texas had expanded Hubbles classification scheme into a more complex system that took into account many observed properties of galaxies. De Vaucouleurs produced a pseudo-three-dimensional plot showing the galaxies relationships, nicknamed the Cosmic Lemon due to its shape. De Vaucouleurs included details on bars in galaxies, descriptions of rings of matter visible in them, and an evaluation of how loosely or tightly the spiral arms of a galaxy were wound. He also included evaluative details about the nature of irregular and peculiar galaxies.

The last generation of extragalactic astronomy has moved into far more sophisticated analyses than cataloging. By using the Hubble Space Telescope, astronomers have estimated that some 100 billion galaxies must exist in the cosmos. And the number may be much greater than that. Probably some 2 trillion galaxies existed in the early universe, but it seems clear that galaxies near each other are drawn together by gravity and combine over cosmic time. Despite the universal expansion, then, normal galaxies like the Milky Way are probably made of dozens or more protogalaxies that merged into larger systems. You can see these primitive blobs of matter, bluish protogalaxies, in the early universe within the Hubble Ultra Deep Field pictures.

Perseus A, also called NGC 1275, is an eruptive galaxy at the core of the Perseus Cluster, which is made up of some 1,000 galaxies about 240 million light-years away. The dominant member of the Perseus Cluster, Perseus A is a Seyfert galaxy with an active nucleus, powered by a 340-million-solar-mass black hole in its core. (Credit: Hubble Legacy Archive, ESA, and NASA)

As astronomers have studied greater numbers of galaxies over the past few decades, theyve discovered many things, but one that is impossible to ignore is that the universe is incredibly large. If you look at a galaxy in your telescopes eyepiece tonight, the photons striking your eye have been traveling at the fastest speed there is 186,000 miles per second (300,000 kilometers per second). Nonetheless, they have taken 2.5 million years at that velocity to reach us from the Andromeda Galaxy. And that object is nearly on our cosmic doorstep. Of course, the knowledge of our own galaxy, in a primitive sense, goes back to antiquity. The name Milky Way comes from the Latin via lactea, which derives from the original idea, the Greek term, galaxas kklos, milky circle. The band of Milky Way visible in our sky, most prominently in the summer and winter evenings, is the unresolved light from billions of stars lying along the plane of our galaxy.

But only in the past few decades have we come to understand that the Milky Way is one of the 100 billion galaxies in the universe, and that its disk stretches some 100,000 light-years across. It contains some 400 billion stars, although we dont know exactly how many because dwarf stars are faint and difficult to see over long distances. For decades, astronomers believed the Milky Way was a simple spiral galaxy. But studies in this century have shown the Milky Way is a barred spiral, and that our sun and solar system lie some 26,000 light-years from the center, in one of the galaxys arms.

The Milky Way consists of a bright disk, a slowly spinning platter of stars and gas that contains most of the stars we see. Our sun orbits the center of the galaxy once every 220 million years, meaning that weve rotated around the galactic center about 20 times since the formation of the solar system. Far away, in the center of the galaxy, lies a supermassive black hole containing around 4.3 million times more mass than the sun. In recent times, astronomers have discovered that supermassive black holes in the centers of galaxies are the norm. Nearly all galaxies, except for dwarfs, have them.

The galaxys disk is encapsulated by a halo of a small number of stars, along with huge spheres of ancient stars called globular star clusters, and a big envelope of dark matter. Astronomers dont yet know what dark matter consists of, but they know it is there because of the gravitational influence it has on the visible matter they can observe.

The weirdly distorted elliptical galaxy NGC 474 in Pisces lies at a distance of 100 million light-years. The neighboring spiral galaxy NGC 470 lies just above it. Multiple shells and tidal tails surround NGC 474, caused by interactions with its neighbors and by density waves that propagate through the medium. This mammoth object stretches 250,000 light-years across two and a half times the diameter of the Milky Way. (Credit: P-A. DUC (CEA, CFHT), ATLAS 3D Collaboration)

The Milky Way is hardly alone in the cosmos. It belongs to a group of at least 54 objects called the Local Group of galaxies, a name Hubble gave to this local cloud of objects as he mapped the nearby cosmos. The primary members of the Local Group are the Milky Way, the Andromeda Galaxy, and the Pinwheel Galaxy (M33). But each of these big three spirals has a cloud of attendant galaxies, too. The Milky Ways satellites include the Large and Small Magellanic Clouds, visible to the naked eye in the Southern Hemisphere, and many dwarf galaxies. The diameter of the Local Group is about 10 million light-years, some 100 times the diameter of the Milky Way.

And moving outward into the deeper universe, we encounter more examples of those 100 billion galaxies. These majestic islands of stars and gas exist in groups, like our Local Group, but also in larger assemblages called clusters and very large ones called superclusters. Despite the overall expansion of the universe, meaning that most galaxies are moving away from each other as the cosmos grows, gravity keeps smaller numbers of galaxies bound to each other on their journeys. Our Local Group, for example, is a member of the so-called Virgo Cluster of galaxies, named so because its richly populated center lies in the constellation Virgo in our sky.

The Virgo Cluster contains at least 1,500 galaxies and is centered some 54 million light-years from Earth. You can see some of the brightest galaxies near the core of the Virgo Cluster in amateur telescopes, in an array called Markarians Chain. This line of galaxies contains supermassive elliptical galaxies such as M84 and M86, and a variety of spiral galaxies, too. For backyard astronomers, this playground of galaxy types is one of the really entrancing areas of the sky, and it is best visible on springtime evenings under clear, moonless conditions.

Most of the Virgo Cluster galaxies contain supermassive black holes in their centers. M87 is quite an example. Whereas the Milky Ways central black hole weighs in at 4.3 million solar masses, the colossal black hole inside M87 contains an estimated mass of 5 billion to 7 billion suns, some 1,000 times more massive than ours. M87 is one of the largest galaxies in our part of the universe it is a so-called cD galaxy, short for centrally dominant and it has eaten many of the smaller galaxies that once surrounded it. Thats what massive galaxies do they consume their neighborhood partners.

One of the greatest edge-on galaxies in the sky, and the one most people say looks like a flying saucer, is the Sombrero Galaxy (M104) in Virgo. It consists of a great rotating disk with a prominent dust lane edging it, consumed by a glowing halo of gas and stars. It lies 43 million light-years away and is about half the size of the Milky Way, sporting a diameter of 49,000 light-years. (Credit: NASA and the Hubble Heritage Team (AURA/STScI))

A cluster containing 1,500 galaxies is one thing, but much larger assemblages of galaxies also exist. The Virgo Cluster itself is a member of the so-called Virgo Supercluster, which holds thousands of galaxies on a scale an order of magnitude larger yet. The Virgo Supercluster holds our Milky Way, the Local Group, the Virgo Cluster, and altogether some 100 galaxy groups and clusters. This amazingly large framework stretches some 110 million light-years across, and is one of about 10 million superclusters that make up the entire cosmos.

Despite the huge number of galaxies existing in the Virgo Supercluster, astronomers now know that most of the space in this volume is essentially empty. The diameters of these great voids range from dozens to hundreds of millions of light-years. Filamentary chains of galaxies wind their way around the dark, empty spaces. On large scales, galaxies in clusters and superclusters are like soap bubbles, with galaxies coating the surfaces and voids lying in between.

The Whirlpool Galaxy in Canes Venatici, another galaxy near the Big Dipper, is also known as M51 and is a top telescope target. An interacting pair of galaxies, the Whirlpool is being passed by a little interloper, NGC 5195, which is drawing material off one of the larger galaxys spiral arms. The pair lies 23 million light-years away, and M51s disk stretches across 60,000 light-years. (Credit: Tony Hallas)

By the end of the 1980s, astronomers had identified the Great Wall, a sheet of galaxies measuring 500 million light-years across. More recently, the Sloan Digital Sky Survey uncovered the Sloan Great Wall, an assemblage of galaxies at least twice the size of the Great Wall, which covers a long dimension of some 1.4 billion light-years.

As astronomers discovered more and more distant galaxies, they found that some large mass seemed to be tugging on the local universe, pulling us in the direction of the southern constellations Triangulum Australe and Norma. Called the Great Attractor, this anomaly, some 200 million light-years away, puzzled astronomers. They eventually discovered that an even larger mass in that direction was pulling us. This mammoth structure, called the Shapley Supercluster, is 650 million light-years away and contains the greatest concentration of galaxies in our local part of the cosmos.

Elliptical galaxies like M49 in Virgo are huge spheres of stars that float in an ellipsoidal cloud. Althoughtheir diameters are often similar to large spiral galaxies, they can hold vastly more mass because they are shaped like a football rather than a disk. This galaxy lies some 56 million light-years away and is one of the more massive galaxies in the Virgo Cluster. (Credit: NASA/ESA/STScI)

Additional surprising discoveries have occurred, too. In 2014, astronomers identified a new supercluster based on the relative motions of galaxies analyzed in a more sophisticated way than ever before. University of Hawaii astronomers concluded that the Laniakea Supercluster exists, and named it after the Hawaiian word for immense heaven.

Laniakea, which is also sometimes called the Local Supercluster, contains some 100,000 galaxies, including the Local Group and the Milky Way. This massive cluster and all its members are traveling together through space, but not all of the galaxies within it are gravitationally bound. Some will splinter apart from the rest of the cluster as time rolls on.

The Laniakea Supercluster has four major components the Virgo Supercluster, the Hydra-Centaurus Supercluster, the Pavo-Indus Supercluster, and the Southern Supercluster.

Altogether, Laniakea contains around 500 galaxy clusters and groups. And surrounding Laniakea in the local universe are other galaxy superclusters the Shapley Supercluster, the Hercules Supercluster, the Coma Supercluster, and the Perseus-Pisces Supercluster. Each of these structures holds hundreds of galaxy clusters and are linked by the fabriclike web of cosmic structure.

Beginning in the 1980s, astronomers found evidence of structures even larger than superclusters. At first, objects now called Large Quasar Groups (LQG) baffled astronomers.

In 1982, Scottish astronomer Adrian Webster found what would become known as the Webster Large Quasar Group, a collection of five quasars, or actively feeding black holes, stretching over 330 million light-years. Now, nearly two dozen LQGs are known. A structure known as the Huge LQG contains 73 quasars over a diameter of some 4 billion light-years. This massive structure, dismissed by some astronomers, may hold the title as the largest collection of related matter in the cosmos.

Truly, the universe is so big that its hard to comprehend. On one hand, the enormity of the universe makes us feel small. Our brief lives happen so quickly, and we wink out, mostly unaware of the incredibly large cosmos around us. But the fact that we are sentient, that we can ponder the stars and galaxies far away from us, makes life in the universe a truly amazing thing. And were just starting to get to know the immense world of galaxies.

David J. Eicher is the editor of Astronomy. His 2020 book, Galaxies: Inside the Universes Star Cities, is available from My Science Shop.

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How Many Galaxies Are There? Astronomers Are Revealing the Enormity of the Universe - Discover Magazine

An international team of astronomers has discovered a close-in super-Earth exoplanet in the HD 164922 planetary system.

An artists impression of the super-Earth exoplanet HD 164922d. Image credit: Sci-News.com.

HD 164922 is a bright G9-type star located approximately 72 light-years away in the constellation of Hercules.

Also known as Gliese 9613 or LHS 3353, the star is slightly smaller and less massive than the Sun and is 9.6 billion years old.

HD 164922 is known to host two massive planets: the temperate sub-Neptune HD 164922c and the Saturn-mass planet HD 164922b in a wide orbit.

The sub-Neptune is 12.9 times more massive than Earth, and orbits the parent star once every 75.8 days at a distance of 0.35 AU (astronomical units).

The Saturn-like planet has a mass 0.3 times that of Jupiter and an orbital period of 1,201 days at a distance of 2.2 AU.

In a new study, Dr. Serena Benatti from the INAF Astronomical Observatory of Palermo and colleagues searched for additional low-mass planets in the inner region of the HD 164922 system.

The astronomers analyzed 314 spectra of the host star collected by HARPS-N (High Accuracy Radial velocity Planet Searcher for the Northern hemisphere), a spectrograph on the Telescopio Nazionale Galileo at the Roque de los Muchachos Observatory, La Palma, Canary Islands, Spain.

We monitored this target in the framework of the Global Architecture of Planetary Systems (GAPS) project focused on finding close-in low-mass companions in systems with outer giant planets, they said.

The team detected an additional inner super-Earth with a minimum mass of 4 times that of the Earth.

Named HD 164922d, the planet orbits the star once every 12.5 days at a distance of 0.1 AU.

This target will not be observed with NASAs Transiting Exoplanets Survey Satellite (TESS), at least in Cycle 2, to verify if it transits, the researchers said.

Dedicated observations with ESAs CHarachterizing ExOPlanet Satellite (CHEOPS) could be proposed, but they can be severely affected by the uncertainty on the transit time.

The teams paper will be published in the journal Astronomy & Astrophysics.

_____

S. Benatti et al. 2020. The GAPS Programme at TNG XXIII. HD 164922 d: a close-in super-Earth discovered with HARPS-N in a system with a long-period Saturn mass companion. A&A, in press; arXiv: 2005.03368

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Hot Super-Earth Discovered Orbiting Ancient Star | Astronomy - Sci-News.com

By Fred Watson, Astronomer-at-Large, The Australian Astronomical Observatory

In an international emergency like the present one, you might expect the science of the stars to be the last thing on peoples minds. The problems facing both individuals and governments are infinitely more pressing than events in the depths of space. People are suffering unprecedented hardships.

Yet throughout history, astronomy has shown extraordinary resilience in times of crisis and has kept public support. That resilience will be needed as a major international project, the Square Kilometre Array (SKA), is on the brink of construction.

The SKA will be the worlds largest radio telescope, and Australia will play a leading role in building and operating it. How can this benefit a nation focused on containing a global pandemic?

History shows the science of the stars is no stranger to crisis. Indeed, modern astronomy was born in a time of deep conflict, when the northern provinces of the Netherlands were engaged in difficult negotiations with Spain after 40 years of war.

In 1608, the fledgling telescope came out of obscurity in the hands of Dutch spectacle-makers, and its possibilities for astronomy were recognised. When news of this optical novelty reached Galileo Galilei in Padua the following May, he set about improving it and the rest is history.

By the turn of the twentieth century, astronomical infrastructure had become big business, but two World Wars caused major disruptions. New telescope proposals were put on hold as manufacturers turned their hands to gunsights, rangefinders, binoculars and other optical munitions.

During the Second World War, one British company actually buried the 1.5-tonne mirror for a new South African telescope in a field to avoid possible bomb damage. While delivery of the mirror was delayed until 1948, the telescope was a success, and is still at work today.

Similarly, in the United States, the 200-inch (5.1-metre) mirror for what was to be the worlds largest telescope at the time, at Mount Palomar, California, was cast in December 1934, but the instruments completion was delayed until 1949. Although it is no longer the largest in the world, the Palomar telescope remains among the most effective.

While hardly comparable to a world war, the present crisis constitutes an emergency of grave proportions, and it is important to put a project like the Square Kilometre Array (SKA) into perspective.

When completed, the telescope will provide radio astronomers with the largest and most advanced facility available to them. With an expected working lifetime of more than 50 years, it will explore the whole 13.8-billion year history of the Universe, yielding many exciting discoveries.

And spin-offs from the technologies under development have huge commercial potential, with tangible benefits for economic recovery.

One of the reasons governments fund research into the study of the Universe is that astronomy pushes technology to its limits whether it be low-noise radio receivers, complex data management systems or sophisticated computer algorithms. Wifi, for example, had its origins in Australian radio astronomy a quarter of a century ago.

More immediately, the construction of the SKA offers significant opportunities for local companies. The low-frequency component of the telescope will be built at the Murchison Radioastronomy Observatory in Western Australias remote Wajarri Yamatji country, one of the most radio-quiet places on Earth.

The project has so far spent $330 million in funding from the Australian and WA governments establishing the observatory and building pathfinder instruments.

And on the wider horizon, big science facilities like the SKA require strong international partnerships, with collaboration among the projects 14 member states representing a further positive outcome. Along with South Africa, where the mid-frequency component of the telescope will be located, Australia can expect its scientific standing to be further enhanced as one of the SKA host nations.

Although technological spin-offs are an important outcome of astronomical research, it is pure curiosity that is the ultimate driver. We are an inquisitive species, and the quest to know is what motivates researchers.

But it also inspires the rest of us with the staggering beauty of the universe and the appeal of scientific understanding. For youngsters in particular, that can prepare them for the jobs of the future, shaping an agile knowledge economy for our nation.

If the lessons of history are anything to go by, the SKA will be unlocking the secrets of the universe long after COVID-19 has subsided into memory. And that will be something of which we can all be proud.

Fred Watson, Astronomer-at-Large, Department of Industry, Science, Energy and Resources, Australian Astronomical Observatory

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The Royal Institution of Australia has an education resource based on this article. You can access it here.

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Why astronomy matters in times of crisis | Cosmos - Cosmos

Saturday, May 16The Moon passes 4 south of Neptune at 11 A.M. EDT. Two hours before sunrise, the pair are 6.5 apart and low on the eastern horizon shortly after rising. Follow them upward as the sky lightens with dawn. The Moon is just 33 percent lit and waning, while Neptune glows at magnitude 6, its disk appearing just 2" across. The nearest bright star is magnitude 4.2 Phi () Aquarii, a red-hued star that offers a glimpse of our Suns future. Currently in the red giant phase of its life, Phi is more than 260 times as luminous as the Sun and almost 39 times as wide. The star will eventually run out of nuclear fuel and its core will turn into a tiny white dwarf, lighting up what once was the stars own atmosphere as a beautiful planetary nebula.

Sunday, May 17Mercury passes 7 north of Aldebaran at 5 A.M. EDT. Because the pair trails the Sun in the sky, they wont be visible until sunset. About 20 minutes after sunset, the sky will still be bright. At that time, Mercury will hover just 9 high, with Aldebaran a mere 3 above the horizon. The two are now nearly 8 apart. Venus is roughly 9 northeast of Mercury, both brighter and higher in the sky, making it easier to spot. The two planets are drawing closer and will pass within 0.9 of each other in just a few days.

Monday, May 18The Moon reaches apogee at 3:45 A.M. EDT, when it will be 252,018 miles (405,584 km) from Earth. Rising just after 4 A.M. local time, our satellite is a smidge less than 17 percent lit and waning fast. Look for a mere sliver of a crescent in the southeast before sunrise, hanging against the brightening backdrop.

Above it in the sky is the Square of Pegasus, outlined by Alpheratz, Scheat, Markab, and Algenib. A little less than 20.5 west of Markab is the supergiant star Enif (Epsilon [] Pegasi), which represents the nose or muzzle of the flying horses figure. Coming in at roughly 150 times the diameter of our Sun, if placed in the center of our solar system, Enif would reach halfway to Venus. To the south of Enif are Alpha () and Beta () Aquarii, which are roughly as bright as Enif. The three also sit at roughly the same distance from Earth. Astronomers think the trio may have been born in the same group of stars, slowly drifting apart over the past 15 million years.

Tuesday, May 19Jupiter and Saturn rise in the southeast not long after local midnight, climbing higher in the sky as the morning hours tick by. The gas giants stand about 4.7 apart, glowing at magnitudes 2.5 and 0.5, respectively.

Once youve found the planets, draw an imaginary line between them. Halfway along that line, glance just over 1 due south to find M75 (NGC 6864), a tightly packed globular cluster considered to have the densest core of all Messiers globulars. This cluster is so dense, in fact, that it still appears starlike in binoculars, and apertures of 10 inches or larger are required to truly begin resolving the clusters stars. The 13-billion-year-old sphere of stars contains about 400,000 members and sits roughly 67,500 light-years from Earth.

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The Sky This Week from May 15 to 22 - Astronomy Magazine

Section 4

Our final section encompasses parts of Canes Venatici, Coma Berenices, and Virgo.

For a whale of a view, slide about 3.5 east-northeast of NGC 4414 to NGC 4631. Popularly known as the Whale Galaxy, this 9th-magnitude tapered monolith (oriented roughly east to west) is replete with dark vapors in a delicate embrace. Star clumps pepper the 15'-long disk like snowballs on the side of a house. For a triple treat, check out NGC 4627, a magnitude 12.5 dwarf elliptical galaxy 3' to the north, and its equally slender partner, the Hockey Stick (NGC 4656/7), a magnitude 10.5 edge-on barred spiral 30' to the southeast.

Next is a different sort of pinwheel. NGC 4725 is a peculiar one-armed spiral a transition system between a normal spiral and a barred spiral that forms one of the most complete rings of any galaxy known. To find this magnitude 9.5 gem, look 2 south and slightly west of 31 Com, which lies near the North Galactic Pole. Through a 4-inch scope, the galaxys inner region displays a bar that connects a bright, broken inner ring surrounded by a fainter lens of light.

To find our next treat, travel westward to a point 2 due east of 17 Com. There, youll find the Needle Galaxy (NGC 4565). This magnitude 9.5 wafer of light has two 8'-long threads of light extending from the galaxys slightly swollen belly like silk from a spiders abdomen. A 4-inch telescope at high power will resolve NGC 4565s classic dark lane, which cleanly divides the galaxys bright hub into two distinct ovals.

The last object is the Lost Galaxy (NGC 4535). While relatively bright (magnitude 10.5), this barred spiral is of low surface brightness, so its a challenge to small-scope observers. The 7'-long glow lies 2 northwest of 31 Vir and, in a 4-inch scope, shines as a circular patch of ill-defined light. Views through 12-inch and larger scopes bring out the spirals main, S-shaped arms within what I describe as extragalactic ectoplasm.

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Observe edge-on and face-on galaxies | Astronomy.com - Astronomy Magazine

Hawaii Islands 12 observatories have been cleared to resume operations by state officials. With travel largely on hold, many observations will now be made from home.

Both state and county authorities in Hawaii have begun relaxing lockdown restrictions that closed many businesses statewide in March. One of the first industries granted permission to reopen by Governor David Ige was astronomy.

The pandemic was the second time in less than a year that Mauna Keas telescopes had to shut down. The first closure was during the anti-TMT protest in the summer of 2019.

Bringing the multi-million dollar telescopes back online is a lot more complicated than turning the lights on. Ivan Look, operations manager at the Canada-France-Hawaii Telescope, told HPR that the major component of regular maintenance is replenishing the coolant that keeps astronomical instruments chilled.

Theyre so sensitive that they need to be super cold in order to provide the clear images that we need, Look said.

Super-cold is not an exaggeration. Some observational tools are kept at temperatures as low as minus 400 degrees Fahrenheit. Maintaining that frigid temperature requires the use of specialized coolant that needs to be regularly replenished, sometimes daily.

If technicians cant reliably access the summit, a telescope may be placed into a safe mode to protect the instruments from damage if they warm up. Look says re-cooling them can take a long time, as in the case of one lunar observation device.

"If that instrument was to warm up, it takes 21 days for us to get all the way back down to cold, he noted.

The Canada-France-Hawaii Telescope has a system that allows some maintenance to be done remotely, minimizing the need to send technicians to the Mauna Kea summit. Look says that capability was a major factor in allowing him to get the telescope operational within 24 hours of the governors announcement, although other telescopes take longer to reboot.

There have also been costs to science. Astronomers have not been on-sky, as they say, in almost two months, according to John OMeara, the chief scientist at the W.M Keck Observatory in Hilo.

We executed zero observing since the governors lockdown, he noted.

Half of the major telescopes worldwide have been shut down, according to OMeara. Some of those projects can be rescheduled, like seasonal observations of the center of the Milky Way or hunting for planets outside our solar system.

Other celestial observations may never be made up. So-called transient events happen with little to no warning and are often impossible to predict.

A supernova goes off, and you never knowwhen its going to happen. But when it happens, you want to catch it. That type of science could have been executed, but I cant point at a specific thing, OMeara said.

He added those types of decisions are often made in real time, when an event occurs. A recent example is the sudden appearance of Omuamua, a mysterious, cigar-shaped object from interstellar space that briefly visited our solar system in 2017.

With worldwide travel largely on hold, OMeara says Keck has beefed up its remote-observing capability. Half of observations made by the Keck telescopes were already being conducted by astronomers operating from remote sites. But some of those sites are also closed as a result of the pandemic. So like many of us, astronomers are now learning how to work from home.

In some cases astronomers are observing on their laptops or computers at home. We colloquially call this pajama-mode observing, OMeara jokes.

Despite the shutdown restrictions, local observatories have been keeping busy during the lockdown. Scientists analyzed previously collected data, while summit technicians have been training on new skills and working on other projects as allowed.

One machinist with the Canada-France-Hawaii Telescope designed and fabricated almost 300 no-touch door openers, which were disturbed to hospital workers in Hilo.

But for now, Hawaiis observatories are back on sky, hunting for the secrets of the universe. Sometimes in pajamas.

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Hunting The Secrets Of The Universe In Pajamas, Astronomers Go Back To Work - Hawaiipublicradio

In an international emergency like the present one, you might expect the science of the stars to be the last thing on peoples minds. The problems facing both individuals and governments are infinitely more pressing than events in the depths of space. People are suffering unprecedented hardships.

Yet throughout history, astronomy has shown extraordinary resilience in times of crisis and has kept public support. Today, that resilience will be needed as a major international project, the Square Kilometre Array (SKA), is on the brink of construction.

The SKA will be the worlds largest radio telescope, and Australia will play a leading role in building and operating it. How can this benefit a nation focused on containing a global pandemic?

Read more: The science behind the Square Kilometre Array

History shows the science of the stars is no stranger to crisis. Indeed, modern astronomy was born in a time of deep conflict, when the northern provinces of the Netherlands were engaged in difficult negotiations with Spain after 40 years of war.

In 1608, the fledgling telescope came out of obscurity in the hands of Dutch spectacle-makers, and its possibilities for astronomy were recognised. When news of this optical novelty reached Galileo Galilei in Padua the following May, he set about improving it and the rest is history.

By the turn of the twentieth century, astronomical infrastructure had become big business, but two World Wars caused major disruptions. New telescope proposals were put on hold as manufacturers turned their hands to gunsights, rangefinders, binoculars and other optical munitions.

During the Second World War, one British company actually buried the 1.5-tonne mirror for a new South African telescope in a field to avoid possible bomb damage. While delivery of the mirror was delayed until 1948, the telescope was a success, and is still at work today.

Similarly, in the United States, the 200-inch (5.1-metre) mirror for what was to be the worlds largest telescope at the time, at Mount Palomar, California, was cast in December 1934, but the instruments completion was delayed until 1949. Although it is no longer the largest in the world, the Palomar telescope remains among the most effective.

Read more: Copernicus' revolution and Galileo's vision: our changing view of the universe in pictures

While hardly comparable to a world war, the present crisis constitutes an emergency of grave proportions, and it is important to put a project like the Square Kilometre Array (SKA) into perspective.

When completed, the telescope will provide radio astronomers with the largest and most advanced facility available to them. With an expected working lifetime of more than 50 years, it will explore the whole 13.8-billion year history of the Universe, yielding many exciting discoveries.

And spin-offs from the technologies under development have huge commercial potential, with tangible benefits for economic recovery.

One of the reasons governments fund research into the study of the Universe is that astronomy pushes technology to its limits whether it be low-noise radio receivers, complex data management systems or sophisticated computer algorithms. Wifi, for example, had its origins in Australian radio astronomy a quarter of a century ago.

More immediately, the construction of the SKA offers significant opportunities for local companies. The low-frequency component of the telescope will be built at the Murchison Radioastronomy Observatory in Western Australias remote Wajarri Yamatji country, one of the most radio-quiet places on Earth.

The project has so far spent $330 million in funding from the Australian and WA governments establishing the observatory and building pathfinder instruments.

And on the wider horizon, big science facilities like the SKA require strong international partnerships, with collaboration among the projects 14 member states representing a further positive outcome. Along with South Africa, where the mid-frequency component of the telescope will be located, Australia can expect its scientific standing to be further enhanced as one of the SKA host nations.

Although technological spin-offs are an important outcome of astronomical research, it is pure curiosity that is the ultimate driver. We are an inquisitive species, and the quest to know is what motivates researchers.

But it also inspires the rest of us with the staggering beauty of the universe and the appeal of scientific understanding. For youngsters in particular, that can prepare them for the jobs of the future, shaping an agile knowledge economy for our nation.

If the lessons of history are anything to go by, the SKA will be unlocking the secrets of the universe long after COVID-19 has subsided into memory. And that will be something of which we can all be proud.

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Technology, international bonds, and inspiration: why astronomy matters in times of crisis - The Conversation AU

Similar to the situation cosmologists confront today, however, the physicists of 1904 had not yet been able to address a few challenges. The medium through which they believed light traveled the luminiferous ether should have induced variations in the speed of light, and yet light always moves through space at the same rate. Astronomers observed the orbit of Mercury to be slightly different from what Newtonian physics predicted, leading some to suggest that an unknown planet, dubbed Vulcan, might be perturbing Mercurys trajectory.

Physicists in 1904 had no idea what powered the Sun no known chemical or mechanical process could possibly generate so much energy over such a long time. Lastly, scientists knew various chemical elements emitted and absorbed light with specific patterns, none of which physicists had the slightest idea how to explain. In other words, the inner workings of the atom remained a total and utter mystery.

Although few saw it coming, in hindsight, its clear that these problems were heralds of a revolution in physics. And in 1905, the revolution arrived, ushered in by a young Albert Einstein and his new theory of relativity. We now know that the luminiferous ether does not exist and that there is no planet Vulcan. Instead, these fictions were symptoms of the underlying failure of Newtonian physics. Relativity beautifully solved and explained each of these mysteries without any need for new substances or planets.

Furthermore, when scientists combined relativity with the new theory of quantum physics, it became possible to explain the Suns longevity, as well as the inner workings of atoms. These new theories even opened doors to new and previously unimagined lines of inquiry, including that of cosmology itself.

Scientific revolutions can profoundly transform how we see and understand our world. But radical change is never easy to see coming. There is probably no way to tell whether the mysteries faced by cosmologists today are the signs of an imminent scientific revolution or merely the last few loose ends of an incredibly successful scientific endeavor.

There is no question that we have made incredible progress in understanding our universe, its history, and its origin. But it is also undeniable that we are profoundly puzzled, especially when it comes to the earliest moments of cosmic history. I have no doubt that these moments hold incredible secrets, and perhaps the keys to a new scientific revolution. But our universe holds its secrets closely. It is up to us to coax those secrets from its grip, transforming them from mystery into discovery.

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Is the Big Bang in crisis? | Astronomy.com - Astronomy Magazine

Spacecraft sleuthing

If J002E3 was, in fact, a spent S-IVB, the next question researchers asked was, Which one was it?

Early test flights with the S-IVB all ended with the third stage splashing into the ocean or disintegrating during reentry. This was also true for the S-IVBs from the Apollo 4, 5, 6, and 7 missions and the Saturn IB flights that carried astronauts to Skylab. The Apollo lunar landing missions numbered 13 through 17 all intentionally crashed their S-IVBs onto the lunar surface to create artificial moonquakes that could be measured by seismic instruments placed by prior landings. But it was the middle Apollo missions (numbered 8 through 12), however, that all intentionally placed their S-IVBs into heliocentric orbits. Any of these missions could have given rise to J002E3.

Further analysis of J002E3 suggested it first left Earth orbit in 1969, narrowing things down to Apollo 9 through 12 (Apollo 8 orbited the Moon in December 1968).

This animation, which has the Sun to the left, shows J002E3 being captured into a chaotic orbit around the Earth.

Paul Chodas and Ron Baalke

Many people find the notion of discovering an intact piece of Apollo-era hardware appealing, and these feelings are amplified by the large size of the Apollo S-IVB. Flown Apollo hardware will always be significant, says Teitel. We've been to the Moon nine times and most of the hardware that enabled those missions was destroyed the Saturn V stages crashed into the ocean or were smashed into the Moon, most of the lunar module ascent stages were smashed into the Moon, and the service modules didn't return. That leaves nine command modules, all of which are on display in museums. Flown hardware has an allure simulators and non-flown items just don't have.

In the case of J002E3, the hardware is still flying. Shortly after its discovery, the object left Earth orbit in 2003, returning to a heliocentric orbit. But researchers suggest that it may yet be recaptured by our planet, with the first opportunity for recapture coming up in the mid-2040s.

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How a long-gone Apollo rocket returned to Earth - Astronomy Magazine