Category Archives: Astronomy

In June, scientists presented compelling evidence that they discovered a massive "hum" of low-frequency gravitational wavesrippling through the universe.

Similar to the ripple effect that occurs when a stone is thrown into the water, a similar phenomenon happens in space. Instead of creating waves that can be seen by the human eye or optical telescopes, the shockwaves that are produced from gravitational energy merging are called gravitational waves.

Physicist Albert Einstein first theorized about the existence of gravitational waves in 1916. But it wasn't until 2015, when the Laser Interferometry Gravitational-Wave Observatory (LIGO) made its first detection of gravitational waves in the universe, that scientists were able to confirm their existence. Since then, the discovery of gravitational waves have allowed scientists to peer inside neutron stars and discover the wobbliest black hole ever detected.

In June, the researchers posited that the massive hum they found was coming from the merging of two supermassive black holes, a type of explosive collision almost too big and too powerful to imagine. But as Salon reported at the time, that wasnt the only candidate as a source.

"We found the choir, but we don't know who's singing in it the pop stars are the supermassive black holes, they're the ones that are the most obvious candidates," NANOGrav scientist Chiara Mingarelli told Salon in June. "However, there are other potential sources of gravitational waves, like quantum fluctuations in the early universe that were driven to the size of the whole universe by inflation."

"We found the choir, but we don't know who's singing in it."

The mission to figure out the source is an international one, as scientists gather data and put it together in an attempt to construct an atlas of this background hum. In an email to Salon, Kai Schmitz, a cosmologist who is part of the international search, said scientists have been sharpening their tools and analyses further. While they dont expect a next round of data sets to be available for another few months and / or years, "primordial gravitational waves from inflation" remains a viable option as a source, Schmitz said.

Taking a step back, Schmitz explained that the possibility that the hum is coming from the merging of two supermassive black holes got the most attention because its the most realistic option. We know that supermassive black holes exist, he said. Most galaxies have supermassive black holes at their center.

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So, it's easy to imagine that when two galaxies merge, each with a supermassive black hole at its center, we ultimately end up with one big galaxy that hosts a pair of supermassive black holes at its center, he said, adding that a possibility like primordial gravitational waves from inflation is more speculative.

Whenever we speculate about gravitational waves from the Big Bang, we need to assume new physics [for example] new interactions, new particles, new forces that go beyond the Standard Model of particle physics, he said. One such scenario of new physics is cosmic inflation, which denotes a stage of exponentially fast expansion in the early Universe.

In other words, the theory of cosmic inflation suggests that right before the Big Bang, a faster-than-light expansion of the universe occurred in the fraction of a second. The rapid expansion occurred due to an unknown source of energy and could be the cause behind the Big Bang.

Whenever we speculate about gravitational waves from the Big Bang, we need to assume new physics."

Recall that gravitational waves are exactly that: ripples in spacetime, perturbations of the fabric of space and time, that stretch and squeeze distances between objects floating through spacetime,Schmitz said. So, the primordial quantum mechanical vacuum fluctuations of the spacetime that are stretched to cosmological sizes during inflation continue to propagate through the Universe in the form of drum roll gravitational waves.

Basically, these waves could be the sounds of the universe forever growing and reproducing. According to the cosmic inflation theory, the universe is eternal, leading to the speculative theory of pocket universes, which would mean that the universe is forever growing and reproducing. Our universe is just one pocket in this.

Another possible explanation is that the hum is also coming from cosmic strings, which are remnants from the early universe when it cooled down quickly and left cracks that are floating around in space. This could mean that we live in a cyclic ekpyrotic model, in which there is no beginning or end of the universe.

However, in order for theorists to find evidence for this theyre going to have to work extra hard.

The standard picture of simple vacuum fluctuations of the spacetime metric will result in a signal that's too weak, Schmitz said. Instead, more complicated processes need to be at work during inflation in order to source a sufficiently strong gravitational-wave signal.

But that doesnt mean its not possible. And Schmitz has some ideas on how to proceed.

Primordial gravitational waves from inflation may lead to an appreciable contribution to the energy density of dark radiation in the early Universe, which is a prediction that can be tested in future observations of the cosmic microwave background and measurements related to Big Bang nucleosynthesis, he said. In other words, the more we study that massive explosions that set our universe in motion, the better we can understand how it came humming along.

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Astronomers search for sources of mind-bending gravitational hum permeating the universe - Salon

Our Milky Way galaxy is a collection of stars famously arranged in a series of spiral arms wrapped around a black hole center. But galaxies aren't the only spiral structures in the universe; individual stars can have swirling, spiral arms as well. And new research is helping to unravel how and why they form.

A new study published July 6 in the journal Nature Astronomy describes how a giant planet might be generating spiral arms in the dusty disk encircling its star. "Our study puts forward a solid piece of evidence that these spiral arms are caused by giant planets," lead study author Kevin Wagner, an astronomer at the University of Arizona, said in a statement.

The exoplanet, called MWC 758c, lies in a very young star system about 500 million light-years from Earth. Its parent star still sits in the center of a protoplanetary disk an amalgamation of dust and rocky objects that have not yet condensed into planets, moons and asteroids.

MWC 758c is a gas giant with about twice the mass of Jupiter. The researchers think this giant planet's gravitational heft allowed it to sculpt the protoplanetary disk in which it sits by stretching the surrounding gas into long arms as the planet orbited its host star. Jupiter may have once played a similar role in shaping our solar system, the team added.

This particular protoplanetary disk was discovered in 2013, but scientists hadn't been able to confirm that MWC 758c existed until now. It turns out, the gas giant was difficult to see because it is extremely red. Longer, redder wavelengths of light are notoriously difficult to pick up with ground-based telescopes. But the team used the Large Binocular Telescope Interferometer in Arizona, one of the most red-sensitive telescopes ever built.

MWC 758c's redness might help to explain why gas giants haven't yet been spotted orbiting other spiral protoplanetary disks. The researchers hope to confirm their observations with the James Webb Space Telescope (JWST) next year.

"Depending on the results that come from the JWST observations, we can begin to apply this newfound knowledge to other stellar systems, and that will allow us to make predictions about where other hidden planets might be lurking," Wagner said.

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Star system with galaxy-like 'arms' may be holding a secret planet - Livescience.com

Who is the greatest astronomer of all time?

The history of astronomy is the story of how humanity has uncovered the secrets of the cosmos, from early astronomers defining the mechanics of the Solar System and how the night sky changes over time, to astrophysicists studying the chemistry of stars, the expansion of the Universe and the warping of spacetime.

Of course, no single astronomer can strictly be deemed 'the greatest'.

Astronomy - like all science - is an accumulative and collaborative effort, each new generation building upon the successes - and mistakes - of the past.

Here we've listed some of the most famous names in the history of astronomy: those men and women who revolutionised our view of the night sky, and helped us understand a little better our own place in the vast cosmos.

Hipparchus was a Greek mathematician and astronomer. None of his works has survived, but we know of them through Ptolemy, last of the ancient Greek astronomers, who made a star catalogue in 140 AD.

After seeing a nova in 134 BC, Hipparchus catalogued the positions of 850 stars in case another popped into view. By comparing his values with some made 150 years earlier, he discovered the precession of the equinoxes. He also founded the stellar magnitude system we use today.

Ptolemy of Alexandria, arguably the greatest astronomer of antiquity, wrote a sweeping synthesis of the astronomical philosophy of the ancient Greeks.

His great book, the Almagest, is a work of awesome complexity in which he represents planetary motion through interlocking circular orbits, with Earth at the centre of the Solar System. This work was the standard textbook on planetary motion until the 16th century, when Copernicus introduced the heliocentric model.

A gifted and greatly respected teacher, Egyptian polymath Hypatia (c350415) was in her time the worlds leading astronomer and mathematician. The widely-educated daughter of the mathematician and Euripides scholar Theon of Alexandria, one contemporary said she far surpass[ed] all the philosophers of her own time.

Although none of her writings survives, she is thought to have edited Book III of Ptolemy's Almagest, a manual on the motions of the stars and planets, and to have constructed astrolabes.

Copernicus wrote one of the most influential books of all time, De Revolutionibus Orbium Coelestium (best known as De Revolutionibus). Daringly, Copernicus the revolutionary showed that planetary motions could be accounted for in a world system with the Sun at the centre.

His change of perspective from the Earth at the centre to the Sun in prime position deeply challenged Christian beliefs. Acceptance of his model didnt come until nearly a century later.

This Danish nobleman unfortunately had his nose hacked off in a duel. A respected astronomer, astrologer and alchemist, his careful observation of the nova of 1572 sparked his interest in astronomy.

By noting that the new star did not change position from night to night (it was far away) he shattered the crystalline Universe of the ancient philosophers who had maintained that the Universe beyond the Moon was perfect and unchangeable.

Possibly the worlds best-known astronomer, Galileo constructed a simple refracting telescope in 1610 and became the first person to use a spy-glass for astronomy. The sheer number of stars, the rough surface of the Moon and sunspots astonished him.

He quickly discovered the Galilean moons of Jupiter and observed the phases of Venus. Everything he saw agreed with the Copernican system which he openly proclaimed, despite strong opposition from the Church.

Johannes Kepler broke free of the classical tradition in astronomy, preferring the methods of science to the thoughts of the ancient sages. In 1600, Tycho Brahe (who had compiled precise observations of Mars) asked Kepler to examine its orbit.

Eight years later, he found not only that it was elliptical, but that all the other planets have elliptical orbits too. Kepler also observed a star in 1604 that suddenly brightened. Now called Keplers star, it was the last supernova seen in the Milky Way.

Hevelius was a wealthy brewer and councillor who made many observations in his spare time. He constructed a large rooftop observatory that employed an enormous telescope of 130ft (40m) focal length to observe the Moon, from which he drew exquisite maps.

His work in positional astronomy led to a star catalogue of 1,564 stars being published the most complete of its day. Hevelius used a quadrant for this and was the last astronomer to do major observational work without the aid of a telescope.

Italian-born astronomer Giovanni Cassini equipped and directed the Paris Observatory from its foundation in 1671 until his death. His observations were focused around the Solar System, where he measured the distance of the Earth from the Sun to an accuracy of 7%.

It was a truly remarkable breakthrough for the time. He also discovered four of Saturns moons: lapetus, Rhea, Dione and Tethys, as well as the gap in Saturns rings that now bears his name.

Isaac Newton, one of the greatest scientists of all time, is mainly remembered for his work on gravity. He also made major contributions to astronomy through his work on optics, experimenting with the surfaces of lenses to see if he could eliminate chromatic aberration.

From this research he correctly concluded that either compound lenses or curved mirrors would be needed to reduce colour distortion. Although he made small telescopes to this (Newtonian) design, only later generations of observers benefited.

John Flamsteed was hand-picked by Charles II as the first Astronomer Royal. Amongst other duties, his job was to improve astronomical methods for finding longitude at sea. The Kings navy was engaged in a global search for colonies, and desperately needed to improve navigation.

Flamsteed, using star positions for this purpose, designed accurate instruments that he used to make a new star catalogue and a star atlas featuring the positions of 3,000 stars.

Edmond Halley made enormous contributions to almost every branch of physics and astronomy. Using his knowledge of geometry and historical astronomy, Halley linked the comet sightings of 1456, 1531, 1607 and 1682 to the same object, which he correctly predicted would return in 1758.

Halley would be long dead by then, which is why not everyone took his prediction seriously, but the comet was named after him nonetheless. He died in 1742 but the comet is his lasting legacy.

Lepaute, with fellow French astronomers and Alexis Clairaut and Joseph Lalande, calculated the return date of Halleys Comet, including complex adjustments for the gravitational influence of Saturn and Jupiter.

For many years she compiled ephemerides (tables predicting the future movements) of celestial bodies for the annual publication of the distinguished French Academy of Sciences, as well as writing on the transit of Venus across the Sun and producing a chart predicting the path of the 1764 annular eclipse.

The dazzling, six-tailed comet of 1744 sparked Charles Messiers interest in astronomy. He was the finest comet hunter of his time, finding a total of 13. In his sweeps of the sky Messier also netted fuzzy objects that looked like comets but were fixed in position.

To aid fellow comet hunters, he listed 103 of these nebulous objects, which included star clusters, gaseous nebulae and galaxies. This compilation is the Messier Catalogue a cornerstone of modern astronomy.

Sir William Herschel has quite a few contributions to his name: discoverer of the planet Uranus, pioneer of sidereal astronomy and designer of what was the worlds biggest reflector from 1789 to 1845.

William and his sister Caroline catalogued thousands of deep-sky objects. William categorised them, along the way developing a theory of stellar evolution and estimate for the size and shape of the Milky Way.

Caroline Herschel achieved many firsts, among them being the first woman to discover a comet (she discovered 8 in her lifetime), the first paid female astronomer and, along with Mary Somerville, the first woman to become a member of the Royal Astronomical Society.

She is also known for her work revising a catalogue of nearly 3,000 stars that had been observed by John Flamsteed, the first Astronomer Royal. She discovered open star cluster NGC 7789, also known as Caroline's Rose Cluster, and on 16 March 2016 received her own Google Doodle.

Mary Somerville was a celebrated scientist of her day who despite the protestations of many of her male peers, published scientific papers on magnetism and the solar spectrum.

She, along with Caroline Herschel, became the first woman to become a member of the Royal Astronomical Society. When she died, she left behind some of the most popular science textbooks of the 19th century.

This German physicist earned his living by making the worlds finest glass for telescopes. In 1813, while researching the refractive properties of glass, he accidentally observed dark lines in the solar spectrum. He investigated them intensively, laying the foundations of spectroscopy.

In the yellow he observed a pair of very dark lines, to which he assigned the letter D. These later became known as the sodium D lines, because the light is absorbed by sodium in the Suns atmosphere.

John was the son of William Herschel. He studied mathematics at Cambridge, and began to assist his father in 1816. In 1834 he went to the observatory at the Cape of Good Hope to survey the southern skies and, while there, discovered no fewer than 2,000 nebulae and 2,000 double stars.

John found himself in the midst of controversy in 1835, when the New York Sun newspaper spun a hoax to boost its sales claiming that he had found animals living on the Moon.

Airy trained as a mathematician in Cambridge and directed the universitys observatory from 1828 at the age of 27. As the seventh Astronomer Royal (1835-1881) he reformed the Royal Observatory Greenwich which, by all accounts, he ruled with a rod of iron.

Airy established a new meridian line at Greenwich in 1851, replacing three earlier meridians. At an international conference held in Washington DC in 1884 this became the definitive prime meridian of the globe.

Huggins founded astronomical spectroscopy, being the first to make intensive investigations of stellar spectra, and was the disciplines pioneer. In 1863 he was the first to show that stars are composed of chemical elements that occur in the solar spectrum.

That same year he scored another first by measuring the redshift of Sirius, following which he measured the velocities of many stars. Hugginss spectroscope also proved that emission nebulae are glowing clouds of gas.

Lowell used his personal fortune to make the first scientific search for life on Mars. Starting in 1894 he spent 15 years observing Mars with an excellent 24-inch refractor at his own observatory in Flagstaff, Arizona.

He produced detailed maps of the Red Planet that recorded seasonal variations as well as linear features but, like other planetary scientists of his generation, he interpreted many surface features of Mars as evidence that an advanced civilisation lived there.

Born in Dundee, Scotland, Fleming devised the Pickering-Fleming system for classifying stars based on the amount of hydrogen observed in their spectra. Abandoned in the USA by her husband while pregnant, she supported herself by working as a maid for Edward Pickering, Director of the Harvard College Observatory, quickly advancing to become a computer at the observatory.

She discovered over 200 variable stars and 59 nebulae, including the famous Horsehead Nebula in 1888. She became an honorary member of the Royal Astronomical Society in 1906.

Annie Jump Cannon was an American astronomer who made her name while working as an assistant at Harvard University in the late 19th century. She, along with many other women astronomers, worked on classifying the spectra of stars.

Cannon is responsible for having simplified Williamina Flemings spectra classification to classes O, B, A, F, G, K and M, which is now the standard.

A pioneer of solar studies, Maunder was one of the first female scientists employed at the Royal Observatory Greenwich, albeit as a low-paid computer. During the 1890s she recorded and photographed sunspots and researched eclipses during expeditions to Algiers, Canada, Lapland and Norway.

She captured the first ever picture of streamers from the Suns corona using a solarscope of her own design and, alongside her husband Walter Maunder, compiled the famous Maunder Butterfly Diagram that tracked sunspot movements over the course of the 11-year solar cycle.

This American solar astronomer was the greatest telescope builder of the 20th century. In 1892 he established the Yerkes Observatory for the University of Chicago, together with its 40-inch refractor which still holds the title of the worlds largest.

He founded the Mount Wilson Observatory, California, which he equipped with the 60-inch and 100-inch reflectors. Hale was also the mastermind behind the 200-inch Palomar telescope which bears his name.

Leavitt found the key to unlock the scale of the Universe. In 1895 she joined Harvard College Observatory, where she measured the brightness (magnitude) of stars by studying its collection of photographic plates. Through this she discovered about 2,400 variable stars.

She noticed that the period of variability of a so-called Cepheid variable indicates its absolute magnitude, from which its distance can be estimated. This provided the first calculation of distances to galaxies.

Hertzsprung discovered the two main groupings of stars the luminous giants and supergiants, and the dwarfs now known as main sequence stars. Henry Norris Russell made the same discovery independently.

Both created diagrams to show the groupings of these stars, which are known today as Hertzsprung-Russell diagrams. Hertzsprung also measured the distances to several variable stars, which he then used as a measuring stick to find the distance of the Small Magellanic Cloud.

In 1916 Eddington received a paper of Einsteins general theory of relativity which explains the force of gravity using geometry. To put Einstein to the test, he observed the total eclipse of 1919 off the west coast of Africa.

His photographs displayed a tiny shift of stars observed close to the Sun, caused by the Suns gravity bending starlight. This observation was the first experimental confirmation of Einsteins work, and it immediately made Eddington world famous.

Edwin Hubble, who trained as a lawyer, was the American observational astronomer who discovered the expansion of the Universe. In 192324 he used the Mount Wilson 100-inch telescope to measure the distances to 18 galaxies an enormous achievement.

When he compared these distances to redshifts measured by others, he found that a galaxys distance is proportional to its velocity. He thus confirmed the idea of an expanding Universe, which is fundamental to cosmology.

Baade made a great discovery in 1944 thanks to wartime blackout conditions in Los Angeles. He had unrestricted access to the worlds largest telescope because many staff at the Mount Wilson Observatory were dragged away on war duties.

He resolved individual stars in M31 (the Andromeda Galaxy) where he discovered that there are two distinct stellar populations of old and young stars. His finding revolutionised research on the evolution of galaxies.

Zwicky was an astronomer who made the startling discovery that most of our Universe is invisible filled with a substance now known as dark matter. In 1933 he examined galaxies in the Coma Cluster and discovered that they were moving too fast to remain bound within it.

Zwicky proposed the idea that mysterious, unseen matter between 10 and 100 times more abundant than visible matter, provided the additional gravitational pull needed to keep the cluster together.

Moore Sitterly was an American solar expert and cataloguer best known for her comprehensive spectroscopic indexes of atomic spectra. Her multiplet tables became the standard reference used by astrophysicists to identify the chemical compenents of stars and are still cited today.

From 1946, she was able to make ultraviolet spectral measurements of the Sun using data from V-2 rockets and later Skylab.

Inspired by Arthur Eddingtons famous trip to observe the 1919 solar eclipse, Payne-Gaposchkin became fascinated by astronomy early on and left her native Great Britain to study at Harvard Observatory.

Carrying on the work on stellar classification of earlier Harvard astronomers like Annie Jump Cannon and Edward Pickering, Payne-Gaposchkin is most remembered for having discovered that stars are primarily composed of helium and hydrogen.

Kuiper, the most distinguished planetary scientist of his time, discovered Uranuss moon Miranda in 1948 and Neptunes Nereid in 1949. A pioneer in planetary atmospheric research, he discovered the existence of a methane-laced atmosphere above Saturns moon Titan and carbon dioxide in the atmosphere of Mars in 1944.

Kuiper is usually best remembered for his prediction of enormous swarms of comet cores and small icy bodies beyond Neptune: the Kuiper Belt.

AmericanCanadian Hogg published the first comprehensive catalogue of variable stars in globular clusters. Working mainly at the Dunlap Observatory in Toronto, she photographed upwards of 2,000 global clusters and discovered hundreds of new variable stars.

The program director of astronomy with the US National Science Foundation and president of the American Association of Variable Star Observers, she published over 200 papers, as well as popularising astronomy through lectures, books and a weekly newspaper column.

Clyde Tombaugh, a self-taught amateur astronomer, joined the Lowell Observatory in 1929 to work on the systematic search for a planet beyond Neptune. On 18 February 1930 he discovered Pluto when it appeared on a pair of photographic plates he had taken in January with the observatorys 13-inch refractor.

Tombaugh doggedly pursued a time-consuming search of the ecliptic for objects beyond Neptune, discovering 14 asteroids in the process.

In 1949 Bernard Lovell set up the UKs first radio telescope in a muddy field at Jodrell Bank, Cheshire. From this humble start he went on to make Manchester a world-class centre for radio astronomy.

At Jodrell Bank he constructed what was once the worlds largest steerable radio telescope, the 75m instrument that bears his name. Completed in 1957, it was the only telescope capable of tracking the first Soviet and American satellites Sputnik and Explorer 1. Its still in use today.

Ryle developed revolutionary radio telescopes and receivers. While at Cambridge University in 1950 he completed the first reliable map of the sky in radio waves, discovering some 50 cosmic radio sources.

His Third Cambridge Catalogue in 1959 led directly to the discovery of quasars when optical observers identified star-like objects at Ryles radio positions. By the 1960s his radio surveys had superseded the steady-state theory advanced by fellow theorist Fred Hoyle.

As the face of The Sky at Night, Patrick Moore introduced millions of viewers to astronomy, setting a record by becoming the worlds longest-serving presenter on the same programme.

Patrick was an active member of the British Astronomical Society and one time director of sections devoted to observing Venus, Mercury and the Moon. In fact, Patrick used sketches of the Moon mad by himself and another astronomer, Percy Wilkins, to produce a large map of the Moons surface. The Russian space agency even requested a copy to help plan the uncrewed Lunik missions.

In 1965 Patrick took a part-time position as the director of the Armagh Planetarium in Northern Ireland. In 1995, he compiled a list deep-sky objects to complement the Messier Catalogue, known as the Caldwell Catalogue, became extremely popular.

Nancy Grace Roman laid the groundwork for our understanding of how galaxies grow and founded NASAs space astronomy programme, which has led to her being known as the mother of Hubble.

At the University of Chicagos Yerkes Observatory she studied the motions of stars that formed in the same cluster as the Plough, but which had drifted apart. She later expanded her research to cover Sun-like stars visible to the naked eye and noticed that where stars orbited in the Milky Way was connected to their metallicity.

At the Naval Research Laboratory she mapped out the Milky Way in new wavelengths, became head of microwave spectroscopy. In 1959 she moved to NASA as head of observational astronomy, becoming the first woman to hold an executive office at NASA an granting her overall responsibility for the agencys space-based observatories.

Eugene Gene Shoemaker is regarded as the founder of 'astrogeology'.

He joined the US Geological Survey and contributed heavily to studies of data collected by the Ranger spacecraft, which impacted the Moon.

For years Shoemaker combined teaching at Caltech with astrogeological studies and took part in observational work searching for comets and near-Earth asteroids, which he undertook with his wife, Carolyn.

The pair's best-known discovery in 1993 was that of Comet Shoemaker-Levy 9, which Carolyn initially described as a squashed comet and which hit Jupiter in 1994.

American astronomer Rubins meticulous observations of the unusual rotation rates in galaxies provided the first direct evidence of dark matter. The theory that most of the matter in the Universe is completely invisible, developed while working at the Carnegie Institution of Washington in the 1970s, was subsequently confirmed in the following decades and revolutionised our understanding of the Universe.

Although unjustly denied the Nobel Prize, her legacy includes several prizes in her name as well as a satellite, an asteroid, a ridge on Mars, a galaxy (Rubins Galaxy, UGC 2885) and a major new observatory, the Vera Rubin Observatory in Chile.

Schmidt specialised in taking the optical spectra of objects known to emit radio waves, exclusively using the 5m Hale Telescope. In 1963 he made a spectacular breakthrough when he realised that the puzzling spectrum of a star-like object at the position of one of Martin Ryles radio sources, 3C273, was highly redshifted.

Therefore, he deduced, it was far beyond our Galaxy. He invented the term quasi-stellar object (that later became shortened to quasar) for these extraordinarily energetic galaxies.

Carolyn S Shoemaker was an American astronomer and one of the worlds foremost hunters of asteroids and comets.

In her lifetime she identified or co-identified over 500 asteroids and 32 comets including, with her astrogeologist husband Eugene Shoemaker and David H Levy, Comet ShoemakerLevy 9. The fragmented comet was observed crashing spectacularly into the planet Jupiter in 1994.

As famous for his science communication as for his experimental results, Carl Sagan began his scientific career with a thesis on the origins of life. He would go on to create the Golden Record shot into interstellar space aboard the Voyager missions, a message to any extraterrestrial civilisations it might encounter, and briefed Apollo astronauts before their flights.

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50 of the greatest, most famous astronomers of all time - Sky at Night Magazine

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Using NASAs James Webb Space Telescope, astronomers have discovered a threadlike arrangement of 10 galaxies that existed just 830 million years after the Big Bang.

Lined up like pearls on an invisible string, the 3-million-light-year-long structure is anchored by a luminous quasara galaxy with an active, supermassive black hole at its core. The researchers believe the filament will eventually evolve into a massive cluster of galaxies, much like the well-known Coma Cluster in the nearby universe.

The results appear in two papers in the Astrophysical Journal Letters.

This is one of the earliest filamentary structures that people have ever found associated with a distant quasar, says Feige Wang, an assistant research professor at the University of Arizona Steward Observatory and lead author of the first paper. Wang adds it is the first time scientists have observed a structure of this kind at such an early time in the universe and in 3D detail.

Galaxies are not scattered randomly across the universe. They gather together not only into clusters and clumps, but form vast interconnected filamentary structures, separated by gigantic barren voids in between.

This cosmic web started out tenuous and became more distinct over time as gravity drew matter together. Embedded in vast oceans of dark matter, galaxies form where dark and regular matter accumulate in localized patches that are denser than their surroundings. Similar to the crests of waves in the ocean, galaxies ride on continuous strings of dark matter known as filaments, says Xiaohui Fan, professor of astronomy at Steward and coauthor of both studies. The newly discovered filament marks the first time such a structure has been observed at a time when the cosmos was just 6% of its current age.

I was surprised by how long and how narrow this filament is, Fan says. I expected to find something, but I didnt expect such a long, distinctly thin structure.

The astronomers made their discovery as part of the ASPIRE project, a large international collaboration led by University of Arizona researchers, with Wang being the principal investigator. The main goal of ASPIREwhich stands for A SPectroscopic survey of biased halos In the Reionization Erais to study the cosmic environments of the earliest black holes. The program will observe 25 quasars that existed within the first billion years after the Big Bang, a time known as the Epoch of Reionization.

The last two decades of cosmology research have given us a robust understanding of how the cosmic web forms and evolves, says team member Joseph Hennawi of the University of California, Santa Barbara. ASPIRE aims to understand how to embed the emergence of the earliest massive black holes into our current story of cosmic structure formation.

Another part of the study investigates the properties of eight quasars in the young universe. The team confirmed that their central black holes, which existed less than a billion years after the Big Bang, range in mass from 600 million to 2 billion times the mass of the sun. Astronomers continue seeking evidence to explain how these black holes could grow so large so fast.

To form these supermassive black holes in such a short time, two criteria must be satisfied, says Wang.

First, you need to start growing from a massive seed black hole, he says. Two, even if this seed starts with a mass equivalent of a thousand suns, it needs to accrete a million times more matter at the maximum possible rate in a relatively short time, because our observations caught it at a time when it was still very young.

These unprecedented observations are providing important clues about how black holes are assembled. We have learned that these black holes are situated in massive young galaxies that provide the reservoir of fuel for their growth, says Jinyi Yang, an assistant research professor at Steward, who is leading the study of black holes with ASPIRE and is the first author of the second paper.

The James Webb Space Telescope also provided the best evidence yet of how early supermassive black holes potentially regulate the formation of stars in their galaxies. While supermassive black holes accrete matter, they also can power tremendous outflows of material.

These winds can extend far beyond the black hole itself, on a galactic scale, and can have a significant impact on the formation of stars. Stars form when gas and dust collapse into denser and denser clouds, and this requires the gas to be very cold. Strong winds from black holes emitting large amounts of energy can wreak havoc with that process and thereby suppress the formation of stars in the host galaxy, Yang says.

Such winds have been observed in the nearby universe but have never been directly observed this early in the universe, in the Epoch of Reionization, says Yang. The scale of the wind is related to the structure of the quasar. In the Webb observations, we are seeing that such winds extend throughout an entire galaxy, affecting its evolution.

Source: University of Arizona

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Astronomers identify earliest strands of the 'cosmic web' - Futurity: Research News

The Role of Artificial Intelligence in Advancing Astronomy and Astrophysics Discoveries

The impact of artificial intelligence (AI) on modern astronomy and astrophysics has been nothing short of transformative. As the volume of data generated by telescopes and other observational instruments continues to grow exponentially, AI has emerged as a powerful tool for processing and analyzing this information, leading to new discoveries and a deeper understanding of the universe.

One of the key ways AI is revolutionizing astronomy and astrophysics is through the use of machine learning algorithms. These algorithms are designed to learn from data, making them particularly well-suited for tasks such as pattern recognition and classification. In the context of astronomy, this means that AI can be used to automatically identify and classify celestial objects, such as stars, galaxies, and supernovae, based on their observed properties.

This capability has proven invaluable in the era of large-scale astronomical surveys, which can generate terabytes of data per night. For example, the Sloan Digital Sky Survey (SDSS), one of the most ambitious and influential surveys in the history of astronomy, has produced a wealth of data on millions of celestial objects. By applying machine learning techniques to this data, researchers have been able to identify rare and unusual objects, such as quasars and gravitational lenses, that would have been difficult or impossible to find using traditional methods.

AI has also played a crucial role in the detection and analysis of gravitational waves, ripples in the fabric of spacetime caused by the acceleration of massive objects, such as merging black holes or neutron stars. The Laser Interferometer Gravitational-Wave Observatory (LIGO) and its European counterpart, Virgo, have made groundbreaking observations of these elusive phenomena, thanks in large part to the use of AI algorithms for filtering out noise and identifying the telltale signatures of gravitational waves in the detector data.

Another area where AI is making a significant impact is in the search for exoplanets, planets orbiting stars outside our solar system. The Kepler Space Telescope, which was launched in 2009, has discovered thousands of exoplanet candidates by monitoring the brightness of stars and looking for periodic dips in their light curves caused by transiting planets. AI algorithms have been instrumental in sifting through the vast amounts of data generated by Kepler, helping to confirm the existence of many new exoplanets and even uncovering some that were initially missed by human analysts.

The potential applications of AI in astronomy and astrophysics extend far beyond these examples. For instance, AI could be used to optimize the design and operation of telescopes, enabling them to observe more efficiently and capture higher-quality data. AI could also be employed to simulate complex astrophysical phenomena, such as the formation of galaxies or the behavior of matter under extreme conditions, providing insights that would be difficult or impossible to obtain through observation alone.

Despite the many benefits of AI, there are also potential challenges and risks associated with its use in astronomy and astrophysics. One concern is that the reliance on AI could lead to a loss of human expertise, as researchers become more focused on developing and fine-tuning algorithms rather than on understanding the underlying science. Additionally, there is the risk of bias and error in AI algorithms, which could lead to incorrect or misleading results if not properly addressed.

In conclusion, AI has already had a profound impact on modern astronomy and astrophysics, enabling researchers to make new discoveries and gain deeper insights into the universe. As AI technology continues to advance, it is likely to play an even more significant role in shaping the future of these fields. However, it is essential for researchers to remain vigilant about the potential risks and challenges associated with AI, ensuring that it is used responsibly and in a way that complements, rather than supplants, human expertise.

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The Impact of AI on Modern Astronomy and Astrophysics - Fagen wasanni

The Moon and the Pleiades (M45, up and to the left of the Moon) rise in this shot taken from Portopalo di Capo Passero in Sicily. Credit: Gianni Tumino

Hi folks, tune in every week of 2023 for the best in astronomy from Astronomy Editor Dave Eicher, brought to you by Celestron. Daves weekly video series will cover all the latest sky events, scientific results, overviews of cosmic mysteries, and more!

This week, weve got a great conjunction between the Moon and one of the most famous deep-sky objects the Pleiades (M45). The name is thought to derive from the Greek plein, meaning to sail: Every year when the cluster first became visible, rising in the pre-dawn sky, it marked the beginning of Mediterranean sailing season.

The Pleiades is also known colloquially as the Seven Sisters for the appearance of its brightest naked-eye stars. But the cluster has by some counts over 1,000 members, most of them hot blue young stars. They happen to be passing through an unrelated dust cloud, forming a reflection nebula. Its the closest Messier object, less than 500 light-years distant. Observations from NASAs Kepler space telescope showed that the clustersseven brightest members are variable stars.

For more on observing the Pleiades and other great targets, see Astronomys series of 101 Must-See Cosmic Objects.

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The Moon buzzes the Pleiades: This Week in Astronomy with Dave ... - Astronomy Magazine

The author found this uncataloged dark nebula while perusing the Aladin Sky Atlas. It is surrounded by numerous other fascinating dark dust structures, all silhouetted by the emission nebula IC 1318 in Cygnus. The dark nebula crossing the left side is part of LDN 889. Credit: Rodney Pommier

Astroimaging involves a profound irony. While the goal of photography is to capture light, the majority of what astrophotographers capture in their images is utter darkness. Oh sure, the intended subject will be a star cluster, nebula, or galaxy. But that doesnt change the fact that most of a typical image will consist of dark background sky. Ultimately, astrophotographers produce beautiful images of well, mostly nothing.

However, the sky offers ample opportunities to capture beautiful images of regions of darkness that actually are something: dark nebulae. This class of celestial object receives scant attention from astroimagers, who predominantly target objects that emit or reflect light.

That is regrettable, because dark nebulae are some of the most important structures in the universe and, therefore, worthy imaging subjects for amateur astronomers. If we take a little time to learn about them, youll soon see why.

Astronomers study molecular clouds because they are star-forming regions. New stars are born within them when condensing regions of H2 reach sufficient density to trigger nuclear fusion. But this process of condensation only begins at extremely low temperatures, generally 10 kelvins or less. (Remember that 0 kelvin is absolute zero.) Condensing gas always heats up, however, and if the temperature rises above 4 kelvins, it will begin to expand, halting star formation. Fortunately, dust particles are efficient radiators of heat, so they keep the temperature low and allow condensation to continue.

Ultraviolet light (UV) from newborn stars stimulates the remaining hydrogen in the cloud to emit light at the hydrogen-alpha (H) wavelength of 656.28 nanometers, creating a glowing emission nebula. UV also provides the energy needed to change carbon monoxide and nitrogen on the surface of dust particles into a smorgasbord of more complex organic molecules, including formaldehyde, glycine, and polycyclic aromatic molecules. Once formed, the complex organic molecules circulate within the dust cloud. Indeed, radio observations find dark nebulae harbor about 70 different organic compounds, some of which may be the building blocks of life. Knowing this, who wouldnt want to image dark nebulae?

Dark nebulae abound in the sky, but to be visible to us, they must be silhouetted against backgrounds of either dense star fields or glowing nebulae. Accordingly, we find them along the bright band of the Milky Way, which betrays their otherwise hidden locations.

Astronomers have cataloged thousands of dark nebulae. Some even have nicknames. Pioneer astrophotographer Edward Emerson Barnard made a catalog of 369 dark nebulae found within his wide-field Milky Way images; probably the most famous is Barnard 33 (B33), the Horsehead Nebula in Orion. Astronomer Beverly T. Lynds made an extensive catalog of 1,802 dark nebulae between declinations 90 and 33. Lynds Dark Nebula 881 (LDN 881), in Cygnus, which I nicknamed the Dementor Nebula in the August 2019 issue, is a beautiful example. Both catalogs are available in books and online. Adventurous imagers can also peruse images from the Sloan Digital Sky Survey, available online within the Aladin Sky Atlas (http://aladin.cds.unistra.fr/), and hunt for uncataloged dark nebulae.

You can image dark nebulae with equipment ranging from a DSLR and 50mm lens for wide-field views of the Great Rift in the summer Milky Way to a cooled CCD or CMOS camera attached to a telescope to capture high-resolution images of intricate wisps of dust silhouetted against emission nebulae. When imaging, I divide targets into two categories based on their background: starry fields or H emission nebulosity. I acquire and process images within each category differently.

For this category, I stretch and process the image as I would for any deep-sky object, but avoid using gradient-removal tools. They can mistake dark nebulae for gradients and remove them from the image. Next, I locate the dust clouds. While their positions may be obvious in wide-field shots of the Milky Way, they are often subtle in my images. Areas where background stars are noticeably fewer or absent are clues to their locations. If I scroll the information tool of my image-processing software over suspected dark cloud regions, I can see they have different brightness values than areas I know are true background sky. The key to making a striking image is to accentuate those subtle differences so the dust clouds dont appear to be just another region of background sky.

An effective way to accomplish that is to use the High Pass Filter in Photoshop. Duplicate the image in the Layers palette as a new layer on top. With the top layer highlighted, open the High Pass Filter (Filter > Other > High Pass). The top image will then appear gray. As you slide the filters radius selector from left to right, progressively larger-scale structures within the gray High Pass Filter image will become accentuated, including subtle dust clouds. Smaller dust clouds will be accentuated with smaller radii, while larger dust clouds are more apparent with larger radii. Select the scale for the dust clouds that you wish to start with in your image, then click OK.

We want this image to be starless for subsequent steps. Go to Select > Color Range, select Highlights in the drop-down menu, then click OK to select the brighter stars. Expand the selection with Select > Modify > Expand and enter a value of 6 to 8 pixels, or whatever is needed to include stars halos. Then go to Edit > Cut to remove those stars.

Change the blending mode in the Layers Palette to Overlay and the dust clouds associated with the scale you selected will magically become more apparent in the underlying original image. This action may make other features look worse, so be selective about which accentuated features within the High Pass Filter image you apply to the image. Add a Hide All mask to the High Pass Filter layer, select the Brush Tool, set it to white, and paint over the dust clouds you wish to accentuate. When done painting, blur the edges of the mask with a

Gaussian Blur (Filter > Blur > Gaussian Blur) of several pixels, then flatten the image.

Multiple iterations of this process with the High Pass Filter set to different radii that accentuate dark structures of different scales can bring out a wealth of detail in dust clouds. Some clouds may be slightly darker than background sky and others may be slightly brighter, but it is those differences that reveal their presence as obscuring dark nebulae.

For this category, I acquire H, red (R), green (G), and blue (B) exposures to construct an HRGB image in which I colorize the H data to be red. While there are many often complicated ways to combine H and RGB data, the following technique is simple, fast, and gives good results.

Combine the exposures into separate H and RGB images. Stretch the RGB image as you would for any deep-sky object. However, only gently stretch the H image. While it is tempting to make it bright to show all the nebulosity and dust you captured, doing so will only give it a displeasing salmon color. Keeping the H image dim will give it deep red hues in the final result. Align the H and RGB images.

Copy the H image and paste it as a new layer atop the RGB image. This will automatically convert the grayscale H image to RGB mode and allow you to colorize it later. In the Layers palette, label this layer as H luminance and the layer beneath as RGB. Then remove stars from the H layer using the steps described above. Because stars in the H image are smaller than RGB stars, the former will have a raccoon eyes look in the final image if left in.

Next, we need to provide red color support for the gray H luminance image. Duplicate the H luminance layer as a new layer beneath the original and label it H red. Highlight it in the Layers Palette, then go to Image > Adjustments > Hue/Saturation. In the window that opens, check the colorize box. Slide the hue selector to 0 or 360 (either signifies pure red), set saturation to 100, and change lightness to 50. You now have a deep red version of your H data. Add a Levels adjustment to this layer and move the black point slider to the right until it is just under the left edge of the histogram. That will clip the red hue out of any background sky and dark nebulae while also enriching the red color in the nebulosity. Highlight the H luminance layer in the Layers palette and change the blending mode to Luminosity to put the red color into your H nebulosity data.

Now the magic can begin. Highlight the H red layer in the Layers palette and change the blending mode to Lighten. This compares the brightness values of every pixel between two layers and selects the brighter of the two to display in the final image. This action also blends your brightest red H nebulosity data with your brightest RGB data, giving you the best of both images. Next, fine-tune the result. Highlight the H luminance layer in the Layers palette again. By moving the opacity slider, you can control how much of the final image comes from red H data and how much comes from RGB data. Somewhere around 50 percent usually gives a great look, but adjust it to your taste. When youre satisfied, flatten the image.

Its fine to keep your H nebulosity pure red, but if you want to add some blue that represents Hydrogen-beta (H) emission at 486.1 nanometers, go to Image > Adjust > Selective Color and select Reds in the drop-down menu. Reducing yellow by moving its slider to the left is equivalent to adding blue. Adjust until you get the customary bubblegum color of H plus H emission nebulosity.

Dark nebulae provide dramatic contrast between light and dark features. They often reveal the finest detail discernible in their wispy contours, while providing depth of field because they are clearly in front of background objects. Layers or billowing clouds of dark dust can even add a three-dimensional texture to the image.

So, I encourage you to acquire and process images of dark nebulae and add them to your portfolio. But be careful. When over to the dark side of astrophotography you have crossed, difficult to go back it may be. The results are sure to be fantastic images that will captivate you and your friends.

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Capturing the light in dark nebulae | Astronomy.com - Astronomy Magazine

The early-summer Milky Way stretches across the sky above Skull Rock at Joshua Tree National Park. Credit: NPS/Hannah Schwalbe

In the Northern Hemisphere, the Milky Way is at its best in the summer months. During the winter and spring, the parts of the Milky Way that are visible are subdued, sparse affairs, little more than a vague mist of faint stars breathed on the window of the sky, running down through Perseus and Auriga and falling to the left of Orion. But when summer comes, as dust sheets are whipped off barbecue grills and Bermuda shorts are taken out of their hibernation drawers, the Milky Way is one of the star attractions in the sky.

Summer is when the glittering star clouds of Cygnus are at their highest, a haze that hangs overhead in the brief, darkest part of a balmy summer night. Framing them, the stars of the Summer Triangle Deneb, Vega, and Altair blaze through the night like finely cut jewels. And sweeping along the length of the Milky Way with binoculars or a small telescope reveals a bewildering number of knots and froths of stars and a sparkling treasure chest of nebulae and clusters.

Everyone knows that, right?

Kind of.

Frustratingly, for observers living at mid-northern latitudes (like me, writing this in the UK), a lot of the good stuff is so low in our sky that it is hard to see through all the haze and murk there. Celestial objects our southern friends see high in the sky are often hidden behind trees, buildings, and hills on our skyline. Consequently, many mid-northern observers dont even try for famous objects such as the Lagoon and Trifid nebulae, or star clusters such as M4 and M22. And two of the most famous and striking constellations in the sky Sagittarius and Scorpius are hard to see too, for the same reasons. This is why many observers dont even bother trying to look farther down the Milky Way than the star cluster M11 in Scutum: They think its just not worth it.

But theyre wrong.

For mid-northern observers willing to put in a bit of effort, these famous objects, which theyve never seen and maybe havent even tried to see, can be observed, photographed, and enjoyed. You just have to be in or rather, get yourself to the right place at the right time: somewhere with a low, flat southern horizon, late at night during the end of June and through July.

Yes, your targets will be low in the sky and challenging, but rewarding to finally see with your own eyes which is, after all, one of the most fundamental rewards and appeals of amateur astronomy.

To see these elusive summer objects, you need an observing location with the most advantageous view. Perhaps your favorite spot is just fine, but many people might need to find an alternative site. Unless you know your local area well and already have somewhere in mind, this will mean doing some research, either by driving around until you find somewhere suitable or, if thats not possible, spending some time virtually exploring on Google Maps .

Either way youll be looking for somewhere with a flat and low southern horizon, without tall trees, buildings, or hills to block your view of the sky in that direction.

You will need to be properly dark adapted to see these summer showpieces at their best because they are faint and diffuse, so find somewhere with as little light pollution as possible. Any streetlights, security lights, or illuminated advertisements in their direction will wash nebulae and clusters from the sky. Passing traffic is just as much an enemy as static lights, so find somewhere away from the roads, where you wont be dazzled every few minutes by the retina-scorching headlights of a passing car or truck.

Dark adaptation

You might think that dark adaption is not important when it comes to viewing the Milky Way in summer because the sky is so much brighter than the autumn or winter sky. But thats not the case. Even the lightest balmy summer night, when only the brightest stars, planets, and constellations fight through the twilight, is much darker than daylight. So, the Milky Way will definitely stand out more clearly if you take the time to let your eyes adapt to the low light levels. Get as far away from artificial lights as possible and try to avoid looking at your phone, too, as even a brief glimpse at a dimmed screen is bright enough to ruin your dark adaption.

All these objects will be at their best around midnight through July and into early August, but you will need to do just a little more research before setting off on your summer Milky Way safari. Find a night when theres no bright Moon in their part of the sky, which will wash them from view. The best observing windows this year are between July 10th and 24th.

Some of these objects are visible to the naked eye but others need binoculars or a small telescope to see them. Dont worry, well give you all the information you need to best view each one.

Using binoculars

Although the summer Milky Way can look very attractive to the naked eye, it is much better seen through binoculars. In this case, dont worry too much about knowing what youre looking at or about trying to identify everything you see using a star atlas or a planetarium app on your phone. For a while, at least, just be happy to be a sightseer!

Slowly sweep your binoculars down and across the Milky Way and enjoy all the stars that drift through their field of view. In some places theyll be as thick as diamond dust or pollen grains; in others, they will be packed less densely and youll sense the voids between them. Beautiful knots, chains, and streamers of stars will pass before your eyes as you pan down the Milky Way, and occasionally a star cluster or misty nebula will appear too. Take your time. Dont rush. Just enjoy drinking in the view.

Here are 12 celestial objects for you to track down on your summer Milky Way safari. Youll likely recognize the names of many of them and will have seen gorgeous photos, either taken by amateur astronomers like yourself or by the Hubble and James Webb space telescopes, but some will be new to you. That doesnt matter. Just enjoy looking for and finding this delightful dozen and seeing them for yourself.

This 5th-magnitude globular cluster is only 10,000 light-years away, making it one of the closest globular clusters we know of. Almost a hundred light-years across, its half a million stars can be seen with the naked eye as a smudge with the same apparent diameter as the Full Moon. A pair of binoculars show it as a smoky ball, while even a small telescope will be powerful enough to resolve the stars that surround its bright central core.

Of the many globular clusters in Sagittarius, M28 is a popular target. At 18,000 light-years away, this buzzing beehive of stars has a magnitude of 6.8, which means it is too faint to see with the naked eye. But look at it through a telescope and youll be able to see its bright core and fainter surrounding halo.

This huge, distant cloud of glowing gas isnt named after a ferocious carnivorous plant; instead, it gets its name from the way that its brightest section is split into three very distinct areas, or lobes, by dark dust lanes. With a magnitude of 6.3, M8 can be seen easily through binoculars, while a small telescope will reveal tantalizing hints of detail and structure on nights of clear air and good seeing. Larger-aperture instruments really add depth to the nebula, showing it comprises an emission nebula, a reflection nebula, and those dust lanes too. But dont expect to see the famously vibrant reds and cool blues of this 5,200-light-years-distant cloud through your telescope; they only show up on long-exposure photos.

More than 4,000 light-years away and some 100 light-years wide, the Lagoon Nebula is one of the most famous deep-sky objects in the whole sky. With a magnitude around 6, it is visible to the naked eye at the darkest time of the night as a misty patch and is much more obvious in binoculars as an extended nebulous area. But when seen through a telescope, the Lagoon really comes to life and some dedicated deep-sky observers think it is as beautiful as the Orion Nebula (M42). The Lagoon Nebula is split into two unequal sections by a prominent dark dust lane. To one side of the dust lane, youll see a glittering cluster of stars superimposed in front of a pale gas cloud, while to the other, youll see a large area of much brighter misty nebulosity with many fascinating subtle streamers, whirls, and swirls. Although the nebula is a lovely orange-pink color in long-exposure photos, your eye will only see vague hints of those hues and the nebula will appear as a misty grey patch through your eyepiece.

M21 is a loose open cluster, containing only 57 or so stars, spread out across 20 light-years. With a magnitude of about 6, it is technically a naked-eye object, but in reality youll need a pair of binoculars or a small telescope to pick it out from the bright summer sky. The cluster is very young, only 4.6 million years old, and is nearby, too some 3,900 light-years away.

Visually, this globular star cluster is a quite subdued object. At magnitude 7.6, it is well below the threshold of naked-eye visibility and appears as just a fuzzy star in a pair of binoculars. Through a telescope the view doesnt really improve much, with the cluster resembling a smooth, hazy patch without a noticeably bright core. What makes this 300-light-year-wide ball of stars interesting is that it is not actually part of the Milky Way. Measurements show it lies more than 86,000 light-years from us and belongs to the Sagittarius Dwarf Elliptical Galaxy, making it the first extragalactic globular cluster discovered.

The Hubble Space Telescope has taken thousands of images since it launched, but few have captured the imaginations and hearts of astronomers and the public alike like The Pillars Of Creation. A trio of ragged columns of gas and dust surrounded by glittering stars, the famous pillars are actually only one small part of the Eagle Nebula, a 15-light-year-wide cloud of gas and dust that lies 7,000 light-years from our solar system. Youll need a large telescope to see the pillars for yourself because they are so small and faint, but the nebula surrounding them shines with a magnitude of 6, making it a naked-eye object. Although past studies indicated these structures had been blown away a supernova thousands of years ago and the light from their destruction simply hadnt reached us yet, more recent followup with newer instruments shows they are, fortunately, here to stay for tens of thousands of years. However, nearby starlight is evaporating the pillars, and they wont stick around forever.

Observers like myself who live at mid-northern latitudes are jealous of their southern counterparts because we can never see the beautiful Magellanic Clouds, the stunning Omega Centauri cluster, or Alpha Centauri, because they never rise above our horizon. But even worse, the brightest part of the Milky Way, the combined glow of millions of old stars in its center, never climbs very high in our sky. Photos taken from the Southern Hemisphere torture and torment us daily in books and magazines. We stare longingly at its airbrushed froth of yellow suns, cut across by lacy lanes of dark dust, and imagine what it must be like to see it high in the sky. But we only see it either through or just above the tops of trees, dimmed and muddied by the haze and murk that linger near the horizon. And the farther north you live, the less of the center you can see, because the southern horizon cuts it off.

But if you can find somewhere with a clearer view south, perhaps on a south-facing coast looking out to sea or high on a hill looking across open countryside, the core of the Milky Way is a beautiful sight to the naked eye: a glowing, smoky patch of light the size of your outstretched hand, dappled with light and dark. Through binoculars it is a sublime sight, scattered with gemstone stars and nebulae that look like smudges of chalk dust. If you hear a promising weather forecast, try to get to somewhere that will let you see it. It will be worth the trip.

How to photograph the summer Milky Way

Having seen spectacular images of the summer Milky Way in books and magazines and online, youll want to take your own. But the most jaw-dropping of those images werent taken with phones. Although the cameras that now come with smartphones are incredible and can be set to take long exposures, if you want to take detailed portraits of the Milky Way showing its magnificent star clouds and smoky dust lanes, youll need a more advanced camera. This should preferably be a DSLR on a motorized mount that allows you to take long exposures by tracking the stars as they move across the sky. Single long exposures can reveal a lot of detail, but if you really want to capture the magnificence of the Milky Way, youll need to take multiple exposures and layer or stack them together to make a single, ultra-long-exposure image.

One of the most striking objects in the summer Milky Way is a pattern of eight stars known as the Teapot. Its not a constellation but an asterism, a distinctive pattern or shape of stars that forms part of a constellation. The Teapot is part of Sagittarius, just as the Big Dipper is part of Ursa Major and the Sickle is part of Leo. The Teapot is always low in the sky from mid-northern latitudes, but it genuinely does look like an old-fashioned teapot. If youre blessed with clear skies (and a good imagination), you can even picture the Milky Way as steam rising up from its spout.

To the right of the tilted Teapot of Sagittarius is a graceful curve of stars representing a heavenly scorpion. The brightest of these stars is orange-red Antares, the Rival of Mars, an enormous red supergiant star that dwarfs our own Sun and is even larger than mighty Betelgeuse. First-magnitude Antares is the brightest star in that part of the sky but only the 15th brightest star in the sky as a whole. Long-exposure photos show Antares is surrounded by and embedded in a cloud of dust and gas, which is buffeted by the fierce solar winds gusting from the star.

This globular cluster, which can be found just to the right of ruddy Antares, is one of the closest globulars to us, just 7,200 light-years away. It can be seen with the naked eye at a magnitude of 5.6 and looks like a round smudge through binoculars. Seen through a telescope, which can resolve stars around its edges, M4 is a very pretty cluster. Its a favorite with many summer observers, but looking at it I always feel rather cheated: If there wasnt a cloud of dust lying between it and us it would be a much more striking naked-eye sight in our sky and a finer telescopic object.

Much higher in the sky than M4, globular cluster M107 has a magnitude of 7.9, which means youll only see it through binoculars or a telescope. 21,000 light-years away, this loose globular cluster has a diameter of around 80 light-years and contains around 50,000 stars. In comparison, the great Omega Centauri cluster, much farther south in the sky, has a diameter of 150 light-years and contains an estimated 10 million stars.

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Now is the best time to see the Summer Milky Way | Astronomy.com - Astronomy Magazine

L.L. Bean has just added a third shift at its factory in Brunswick, Maine, in an attempt to keep up with demand for its iconic boot.

Orders have quadrupled in the past few years as the boots have become more popular among a younger, more urban crowd.

The company says it saw the trend coming and tried to prepare, but orders outpaced projections. They expect to sell 450,000 pairs of boots in 2014.

People hoping to have the boots in time for Christmas are likely going to be disappointed. The bootsare back ordered through February and even March.

"I've been told it's a good problem to have but I"m disappointed that customers not getting what they want as quickly as they want," said Senior Manufacturing Manager Royce Haines.

Customers like, Mary Clifford, tried to order boots on line, but they were back ordered until January.

"I was very surprised this is what they are known for and at Christmas time you can't get them when you need them," said Clifford.

People who do have boots are trying to capitalize on the shortage and are selling them on Ebay at a much higher cost.

L.L. Bean says it has hired dozens of new boot makers, but it takes up to six months to train someone to make a boot.

The company has also spent a million dollars on new equipment to try and keep pace with demand.

Some customers are having luck at the retail stores. They have a separate inventory, and while sizes are limited, those stores have boots on the shelves.

Link:

July Astronomy: What's in the North Texas sky this month? - NBC 5 Dallas-Fort Worth

Holland America Lines special 2024 Solar Eclipse cruises aboard Koningsdam and Zaandam will offer travelers more than just a unique viewing opportunity for the total eclipse.

The cruise line will now include insightful guidance and immersive programming from astronomy experts onboard. This will make the cruises truly unforgettable for everyone, with deeply enriching lectures and activities for all guests.

Aboard Koningsdam and Zaandam, both of which have special voyages planned to bring cruise guests right into the best possible viewing locations for the April 8 eclipse, astronomy experts will add even more enrichment to the sailings with special lectures, activities, and insights.

University of California San DiegoProfessor of Astronomy and AstrophysicsAdam Burgasserwill be aboard the Pinnacle-class Koningsdam, offering detailed lectures prior to the eclipse and helping guests make their own eclipse viewers for optical safety.

During the event which should last approximately 4 minutes and 28 seconds at its peak Burgasser will provide commentary and viewing assistance.

Were positioning our ships in the perfect location for guests to see the eclipse, saidBill Prince, vice president of entertainment forHolland America Line. For many, this is a once-in-a-lifetime experience, so being able to receive the guidance of a renowned physicist likeDr. Burgasseris an exciting opportunity for our guests. Were known for creating immersive programming, and this will be an unforgettable live event.

Koningsdam will be sailing a 22-night Solar Eclipse Cruise that will depart San Diego on April 5. The ship will call on Cabo San Lucas the day before the eclipse, and will be positioned offshore for unimpeded viewing on April 8.

Other ports of call include Puerto Vallarta and several top Hawaiian destinations, before the ship reaches Vancouver, Canada on April 27, in preparation for the Alaska sailing season.

This first total solar eclipse inNorth Americain seven years is something astronomers amateur and professional are all excited to observe, and theres no better or unique place to observe it than at sea off the coast ofMexico, said Burgasser.

I look forward to joiningHolland America Lineguests aboard Koningsdam to witness this phenomenon and help them better understand the science and history behind it.

Zaandam will be sailing a 14-night Solar Eclipse & Mexican Riviera cruise for the event, departing from San Diego on March 30 and calling on several Mexican ports of call along the way before being in Puerto Vallarta on the day of the eclipse. After the stunning astronomical event, the cruise will continue to Loreto, La Paz, and Cabo San Lucas before returning to San Diego on April 18.

On board, guest presenter Jim McParlandwill lend his expertise to the eclipse experience, offering lectures and demonstrations as Zaandam is positioned for total viewing.

The total solar eclipse of April 8, 2024, is a highly anticipated astronomical event. Because of its location, cruise lines can make the most of the eclipse by offering spectacular viewing opportunities in the path of totality a thin region where the visual eclipse will be most spectacular and most prolonged. Totality is when the moon completely obscures the sun and the brilliant solar corona is visible.

The maximum width of the totality band will be 123 miles (198 kilometers) wide, covering just one-fortieth of a percent of the earths surface.

Because ships can remain at sea and away from any obstructing features like skylines, mountain ranges, and pollution, eclipse viewing from the deck of a cruise ship promises to be spectacular.

Furthermore, depending on local conditions, cruise ships may even be able to reposition themselves in case of poor weather or cloud cover so guests onboard dont miss prime viewing opportunities.

This particular total eclipse will be the first to have totality visible in Canada since 1979, the first in Mexico since 1991, and the first in the US since 2017. The next eclipse will occur on October 2, 2024, but that event will be entirely over the Pacific Ocean and well away from established cruise travel regions.

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Holland America Line Adds Astronomy Experts to Eclipse Cruises - Cruise Hive