Sixty-six million years ago, the dinosaurs had a really bad day.

Not just them, either, since 75% of the species on Earth disappeared in a short time. Theres no doubt now that the main driver of this mass murder, called the K-Pg extinction event, was an enormous asteroid (or possibly comet) impact, an object 10 kilometers across that slammed into the planet just off the coast of modern-day Yucatan. This created a crater some 150 kilometers wide, and instigated a series of catastrophic events both immediate and long-term that wiped out most of the life on Earth.

We dont know what the exact date of this event was, but scientists are honing in on the time of year it was, the season. And its looking like life on Earth had a really, really bad June.

Knowing the time of year of the impact is important because of the effect on biology. For example, a species might be more likely to survive if the event happened after they lay their eggs in a protected place. Even if the adults are wiped out a second generation could still have a chance. It also effects how long it might take for plants to regain their place in the environmental niches opened by the impact, or what specific species might dominate in the short term after the impact.

There has been previous work done that points toward the impact happening in late spring/early summer, but there hasnt been a consensus. However, a new paper just published has some pretty good evidence that it was this time of year when the hammer fell.

In the new research, scientists turned to the Tanis fossil site in western North Dakota, a part of the vast Hell Creek Formation, a geological layer that spans several states and is dated to have been laid down at the time of the impact. Some 10 13 minutes after the impact in Mexico, immense seismic waves passed the Tanis site, causing flooding that most likely came from the nearby Western Interior Seaway, a huge but shallow sea that ran north/south across western North America at the time. This in turn created whats called a seiche, a huge standing wave in water that can generate waves a hundred meters high. This is similar, for a much smaller and mundane scale, to when you scooch back and forth in a bathtub in time with the waves generated, amplifying the crests enough that you can splash water out of the tub.

Now picture the tub being a lake, and the waves reaching 20 stories high.

This happened quite suddenly at Tanis, and the geography of the area makes it possible to actually get extremely fine time resolution of the events. Its also replete with fossils, including fish, insects, plants, and more. Heres where this gets cool: By examining these fossils, its possible to figure out the time of year of the impact.

For example, the scientists looked at sturgeon fossils, specifically a pectoral fin spike. Sturgeon are anadromous, which means they migrate from river to sea and back again, so they go from fresh to salty water, and this migration is seasonal. Bone growth in sturgeon depends on time of year, health, and so on, and they can see that the growth of this spike bone stopped suddenly at the tip, certainly due to the fishs death by the impact.

But the key here is in the elemental content of the bone. An isotope of oxygen called oxygen-18 fluctuates in a yearly pattern in the bones corresponding to migration; when the fish is in fresh water theres not as much oxygen-18, and when theyre in salty seawater it is incorporated more strongly. The opposite is true for an isotope of carbon called carbon-13; its absorption in the bone is heavier in fresh water and lighter in seawater.

The scientists saw these abundances going up and down in the fish bone as they traced them toward the tip, and theyre out of phase (when one goes up the other goes down, and vice-versa), a clear indication of the seasons. Plotting these fluctuations, the scientists found the impact happened in late spring or early summer.

They found the same thing in mayflies. These insects burrow into wood to lay eggs, which hatch during a very brief interval of less than a few weeks in early spring. The fact that adult mayflies were found fossilized shows that the impact happened while adult mayflies were active, so after the eggs hatched. The bodies are also fragile, so the impact must have happened early in their adulthood, or else intact fossils wouldnt have been found.

On top of that, some insect larvae eat leaves, leaving characteristic tracks in the leaves (this is called leaf-mining, an adorable term). Intact furrows in some fossilized leaves including some still attached to branches show that larvae were actively feeding at the time of impact, again pointing toward spring/summer, when larvae are busy building mass for metamorphosis.

I find this all rather amazing. I remember when the asteroid impact hypothesis was very controversial, and now its not only accepted, but evidence has popped for it in unlikely events like a million-year-long volcanic eruption halfway around the planet due to the force of impact opening up underground magma pipes, allowing the eruption to increase (though the contribution of this to mass extinctions is still being argued over).

And now not only is it accepted, but scientists can narrow down what month it happened in.

Big asteroid impacts are exceptionally rare, and global mass extinctions from them even more so. Still, the more we know about such events the better. You never know what piece of evidence will lead to a discovery that helps us better prevent an impact, or understand what the consequences are if we dont.

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The last spring of the dinosaurs - SYFY WIRE

A deadly new class of synthetic opioids has been identified in cities throughout the United States at a time when fatal drug overdose rates are soaring.

Forensic scientists have identified nitazenes on streets throughout the country. The nitazene class has proven even stronger than fentanyl, the synthetic opioid the extreme potency of which is responsible for the majority of deadly overdoses in the U.S.

There's probably about five to 10 drugs that make up this medicine class right now that have been identified on the market, said Alex Krotulski, an expert in nitazenes at the Center for Forensic Science. They're really spread through all areas throughout the U.S. Usually, we see them epicentered around places in the Midwest and then, they sort of proliferate out from there.

DOCTORS CAUTION CDC AGAINST CHANGING 'FULLY VACCINATED' STANDARD FOR NOW

The most commonly found drugs within the nitazene class are isotonitazene, metonitazene, and protonitazene, which have been found in many states such as Texas, Ohio, Indiana, New York, and New Jersey. Experts estimate the potency of the nitazene class to range from twice to 10 times as fatal as fentanyl, which is sometimes undetectably laced in heroin or cocaine and can be fatal in even miniscule doses.

The majority of these nitazene analogs are more potent than fentanyl, especially the ones that we see. I think that's probably by design, Krotulski said. You've got drugs that are, say, one to two times more potent than fentanyl, that are two to three times more potent, and now you've got drugs that are 10 times more potent than fentanyl.

The onset of the pandemic in Spring 2020 brought with it mandatory quarantines and social distancing, conditions that facilitated skyrocketing drug overdoses. The Centers for Disease Control and Prevention reported in July that fatal drug overdoses in 2020 increased by nearly 30% over the previous year, reaching an all-time high of more than 93,300. Opioids were the cause of a majority of overdose deaths in every state as well as D.C. Fatal overdoses caused by opioids specifically increased from 50,963 in 2019 to an estimated 69,710 in 2020.

Fentanyl and other synthetic opioids were involved in more than 60% of all fatal drug overdoses in 2020. Drug users who misuse nitazenes will often use them in concert with another substance, sometimes unknowingly. Drugs such as heroin or cocaine are often laced with trace amounts of extremely potent synthetic opioids to make them cheaper to traffic.

"Nowadays with the overdose epidemic, we're seeing a lot more poly drug use so you have to examine the drugs by themselves ... Then you also have to take into account the fact that these drugs are being found and used with fentanyl. And when you get into that scenario, you're just adding things together, adding potent on top of potent," Krotulski said.

Versions of fentanyl that have been chemically altered to be more potent, also called fentanyl analogs, have increased in popularity in recent years due to the governments whack-a-mole-like approach to regulating the synthetic drugs. Since 2018, all fentanyl analogs have been categorized as schedule 1 substances, meaning they have extremely high abuse potential and no medical benefit.

When a drug is scheduled with the Drug Enforcement Administration and becomes harder to find, a newer drug takes its place. Enter: nitazenes.

We're seeing the same thing happen where with fentanyl analogs, one drug would be prevalent, it would be scheduled by the DEA, that drug would go away, and then a new drug would be introduced into the market, Krotulski said. So, we're seeing this sort of cyclic pattern, if you will, of one drug after another after another after another.

The synthetic opioids have also been identified in the District of Columbia, where opioid overdose deaths in the 12 months leading up to May 2021 reached about 498. D.C. ranks second behind West Virginia in the number of deaths due to opioid overdoses during the pandemic, according to an analysis from the Washington Post. Alexandra Evans, a chemist at the D.C. Public Health Lab was the first in the district to identify the drugs after finding residue on a used needle collected from the citys needle exchange locations for intravenous drug users to discard used paraphernalia and get new supplies.

We knew that it was a new type of synthetic opioid very quickly, based on its instrumental analysis report, Evans said. Our lab had heard about the discovery of nitazenes in other cities beginning in 2019. We were familiar with this drug class, and the specific drugs within it.

CLICK HERE TO READ MORE FROM THE WASHINGTON EXAMINER

The stress of COVID-19 and social isolation have contributed to the roughly 4 in 10 adults in the U.S. who have experienced increased rates of anxiety and depression, according to the Kaiser Family Foundation. Stay-at-home orders during the first wave of COVID-19 also made visiting with or checking in on people suffering with substance use disorders difficult and sometimes impossible.

COVID-19 has been difficult to track, and surges have been difficult to predict. The recent discovery of the omicron variant has concerned public health experts and healthcare workers who are still reeling from roughly 20 months of overcrowded ICUs and strained supplies. While the Biden administration has not indicated it will revert back to early pandemic restrictions such as business closures or stay-at-home orders, the U.S. will continue to beat back renewed surges into next year.

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New synthetic opioid threatens to drive up astronomical overdose rates - Washington Examiner

Weather-wise, spring has hopefully sprung as we begin April. But did you know that many of the prominent winter constellations can still be observed? If the cold and snowy conditions of February and March prevented you from exploring the winter sky, its now time to say farewell to some star patterns that often get overlooked during mid-winter in our region of the country. With public night viewing at Seagrave Observatory and Ladd Observatory closed due to COVID-19, even I did not observe my winter sky friends. Its difficult to set up a telescope in ones backyard with 18 inches of snow on the ground.

Once this column is published, I want you to scan the western sky after sunset to bid goodbye to many of the skies brightest star patterns. See the accompanying star map. Start with Perseus toward the northwest, then move your gaze south (to the left). Here you will encounter Taurus, with the prominent star clusters named the Pleiades (aka the Seven Sisters) and the Hyades. While a binocular view of the Pleiades does show a nice image, the ideal sight you want to achieve is with a telescope under low magnification so the entire cluster fits into the field of view. In a dark, moonless sky, the Pleiades remind me of sparkling diamonds scattered upon black velvet.

Above Perseus and Taurus, youll find Auriga. To the south (left) of Taurus youll encounter the Mighty Hunter Orion. And further to the left will be Canis Major, home of Sirius, the brightest star we can see in our sky other than the sun. Youll find Gemini, the twins above Orion, and this star pattern will be the last of the winter constellations to set below the horizon.

If you dont explore anything else in this region of the heavens before the constellations set, make an effort to observe the Orion Nebula if you havent already done so this past winter season. Usually, the local observatories would have focused on this beautiful region of stellar dust and gas for many weeks, but closures prevented that activity during the winter of 2020-2021. In past columns over the years, I have highlighted this remarkable region of space where new stars are in the process of being born. Following is a brief description.

The grandeur of Orion resides in the region of his sword. Using binoculars, youll see a wispy, hazy patch of green light enshrouding the stars. Using a telescope even under low magnification will reveal a greenish tinged nebula of dust and gas the magnificent Orion Nebula. I never tire of observing this vast dust cloud, often imagining what this region of space will look like when upwards of 1000 stars will be born here.

Mars Still Visible

Due to the orbital paths of Mars and the Earth, when Mars is visible it remains so for an extended period of time. The contrary is also true. When Mars disappears from view it remains hidden for an extended period of time. Right now, you can still observe Mars, as it resides in the constellation of Taurus. See star map. You may recall that Mars and the Earth had a close encounter last Oct. 6, when our two worlds were only 38.6 million miles away from one another. At that time Mars was a very bright pumpkin orange in the night sky and its disk was large enough to see a wealth of detail using a telescope. On April 1 that distance will be 164.5 million miles. Mars will be much dimmer than it was back in October. In fact, it will now be fainter than Taurus brightest star Aldebaran. While the planet will appear small even in a modest-sized telescope, perfect seeing conditions may allow one to discern a Martian surface feature or two. It doesnt hurt to try.

April Lyrids Meteor Shower

I always look forward to a decent display of shooting stars. While the upcoming April Lyrids meteor display on the night of April 21-22 is not a blockbuster event, one can potentially observe upwards of 20 meteors per hour in a dark country sky. The Lyrids appear to radiate outward from an area of sky on the Lyra-Hercules border near the bright star Vega, which will be about 45 degrees (halfway between the horizon and zenith) above the eastern horizon at midnight and well-placed for observing.

A bright waxing gibbous Moon, about 70% illuminated, will somewhat reduce visibility of the fainter meteors. However, it will be located more than 100 degrees away to the west in the constellation of Leo, to the right of the backwards question mark asterism. While still a nuisance light source, the moon shouldnt compromise your observing session. Try to block its brightness using a building or some trees.

These swift and bright meteors disintegrate after hitting our atmosphere at a moderate speed of 29.8 miles per second. They often produce luminous trains of dust that can be observed for several seconds. The moon will set just before 4 a.m. EDT, leaving a little more than an hour of moonless sky before dawns early light will begin to overwhelm the stars and the meteors.

Best of luck in all your observing endeavors.

The author has been involved in the field of observational astronomy in Rhode Island for more than 35 years. He serves as historian of Skyscrapers Inc., the second oldest continuously operating amateur astronomical society in the United States.

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View On Astronomy: April means it's time to say farewell to winter constellations - The Independent

Astronomers havesearched the entire Milky Way to identify the safest places to live.It turns out, we're in a pretty good spot.

But if the past year has made you feel ready to relocate to another planet, you might want to looktoward thecenter of the galaxy, according to the new research.

The new findings were made by a group of Italian astronomers, who studied locations where powerful cosmic explosions may have killed off life. These explosions, such as supernovas and gamma-ray bursts, spew high-energy particles and radiation that can shred DNA and kill life. By this logic, regions that are more hospitable to life will be the ones without frequent explosions, the astronomers reasoned.

"Powerful cosmic explosions are not negligible for the existence of life in our galaxy throughout its cosmic history," said lead author on the new study, Riccardo Spinelli, astronomer at the University of Insubria in Italy. "These events have played a role in jeopardizing life across most of the Milky Way."

Related: 11 fascinating facts about our Milky Way galaxy

In addition to finding the deadliest hotspots, the astronomers also identified the safest places throughout the galaxy's history, going back 11 billion years. The results show that we're currently at the edge of a wide band of hospitable real estate. But in the Milky Way'syouth, the galaxy's edges were a safer bet.

Many factors make a planet habitable. For instance, planets need to be in a Goldilocks zone, where heat and activity from their host star isn't too much or too little it's just right. But in addition to these local conditions, life also has to combat harmful radiation coming from interstellar space.

Powerful cosmic events, such assupernovas and gamma-ray bursts, stream dangerous, high-energy particles at nearly the speed of light. Not only can they kill all the lifeforms we know about, but these particles can also strip entire planets of their atmospheres. After such an event, the scientists believe that planets orbiting nearby star systems would be wiped clear of life.

Related: The 9 real ways Earth could end

"For planets very close to the stellar explosion it is plausible that there is a complete sterilization," Spinelli told Live Science. "In those far away, a mass extinction is more likely."

The authors wrote in the study that a nearby gamma-ray burst may have played a leading role in theOrdovician mass extinction event around 450 million years ago the second largest in Earth's history. While there is no concrete evidence linking a specific gamma-ray burst to this extinction event, the authors think it could be likely, given Earth's position in the galaxy.

Using models of star formation and evolution, the astronomers calculated when specific regions of the galaxy would be inundated with killer radiation. Early on in the galaxy's history, the inner galaxy out to about 33,000 light-years was alight with intense star formation, which rendered it inhospitable. At this time, the galaxy was frequently rocked by powerful cosmic explosions, but the outermost regions, which had fewer stars, were mostly spared these cataclysms.

Until about 6 billion years ago, most of the galaxy was regularly sterilized by massive explosions. As the galaxy aged, such explosions became less common. Today, the mid regions, forming a ring from 6,500 light-years from the galaxy's center to around 26,000 light-years from the center, are the safest areas for life. Closer to the center, supernovas and other events are still common, and in the outskirts, there are fewer terrestrial planets and more gamma-ray bursts.

Luckily for us, our galactic neighborhood is getting more and more life-friendly. In the long-term galactic future, there will be fewer extreme events nearby that could cause another mass extinction.

The new paper's conclusions seem reasonable at first glance, Steven Desch, an astrophysicist at Arizona State University, told Live Science.

"I'm pleased to note that they do seem to put [the research] in a rigorous framework and have realistic expectations about what a gamma ray burst would do, and account for factors that sometimes people forget," such as how the energy and material released by gamma-ray bursts isnt equal in all directions, said Desch, who was not involved with the new work. "I haven't gone through their numbers in detail, but at first glance it's reasonable."

The new research, published in the March issue of the journal Astronomy and Astrophysics, might one day help astronomers decide where to search for habitable exoplanets. But for now technology limits astronomers to only searching nearby areas, Desch said.

Originally published on Live Science.

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Astronomers find the 'safest place' to live in the Milky Way - Space.com

Artificial satellites and space junk orbiting the Earth can increase the brightness of the night sky, researchers have found, with experts warning such light pollution could hinder astronomers ability to make observations of our universe.

There are more than 9,200 tonnes of space objects in orbit around the Earth, ranging from defunct satellites to tiny fragments, according to the European Space Agency (ESA). Now it seems space junk not only poses a collision risk but, together with other space objects, is contributing to light pollution.

Writing in the Monthly Notices of the Royal Astronomical Society, researchers describe how sunlight that is reflected and scattered from space objects can appear as streaks in observations made by ground-based telescopes.

Because the streaks are often comparable to or brighter than objects of astrophysical interest, their presence tends to compromise astronomical data and poses the threat of irretrievable loss of information, the team writes.

But for some instruments, the impact could be greater still. When imaged with high angular resolution and high sensitivity detectors, many of these objects appear as individual streaks in science images, they write. However, when observed with relatively low-sensitivity detectors like the unaided human eye, or with low-angular-resolution photometers, their combined effect is that of a diffuse night sky brightness component, much like the unresolved integrated starlight background of the Milky Way.

Calculations in the report suggest this glow could reach up to 10% of the natural night sky brightness a level of light pollution previously set by the International Astronomical Union (IAU) as being the limit that is acceptable at astronomical observatory sites.

While the researchers say the idea of a natural level of brightness has its own difficulties, they stress further research is necessary, adding that the situation could become worse as further satellites, including mega-constellations, are launched.

Greg Brown, a Royal Observatory astronomer who was not involved in the study, said light pollution was a big problem for astronomers.

Telescopes like the soon-to-be-operational Vera C Rubin Observatory are expecting vast contamination of their images from just the mega-constellations expected in the next few years, which will be difficult and costly to compensate for and do seriously risk scientists missing out on key scientific discoveries, he said.

While Brown said it was unclear whether the assumptions made in the study held true, given changes in satellite design and the difficulty of estimating small space debris, he said astronomical observations would be increasingly affected by such light pollution.

This is definitely the time to be concerned about the future of both professional and amateur astronomy, he said.

Prof Danny Steeghs of the University of Warwick said there was a balance to be struck between the benefits of satellites and their impact on our ability to study the night sky, but agreed light pollution was likely to be a growing, and escalating, problem.

We can, as astronomers, remove or reduce the direct impact on our data somewhat by employing image processing techniques, but of course it would be a lot better if they are not there for starters, he said.

Fabio Falchi, from the Light Pollution Science and Technology Institute in Italy, said the problem was global. The distribution of the space debris is fairly uniform around our planet, so the contamination is already present everywhere, he said, suggesting those responsible for the problem should help to solve it.

Maybe Elon Musk can put his engineers at work to find out a solution, at least to counterbalance a little the damage that his Starlink mega-constellation of satellites is going to make to the starry sky, he said.

While projects have recently begun to clean up space junk, Steeghs said one difficulty was that small fragments could be tricky to sweep up yet could nonetheless contribute to the light pollution.

Chris Lintott, a professor of astrophysics at the University of Oxford, also stressed the need for action. It does seem that simple efforts like building satellites out of darker materials might be very helpful, and I hope operators will take such steps as soon as possible, he said.

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Light pollution from satellites 'poses threat' to astronomy - The Guardian

In March 2020, the Vera C. Rubin Observatory sat partially erected, perched on Chiles Cerro Pachn in the foothills of the Andes Mountains. The Observatory had halted construction of the 8.4-meter telescope and its associated buildings due to the coronavirus pandemic. By October 2020, with safety precautions in place, construction teams began to slowly return to the mountain. Earlier this month, just one year after its unexpected closure, the Rubin Observatory reached a major milestone when crew used a crane to lower the top end of the telescope, weighing approximately 28 tons and measuring 10 meters in diameter, through the observatorys open dome and into its place on the telescope. This was one of the last remaining heavy pieces to be added to the telescope as the project nears completion and looks forward to beginning regular observations in 2022.

Once in operation, the Rubin Observatory will survey the sky above it, capturing images every few nights to create a catalog of data and a map of the visible universe. Astronomers will use this accumulation of roughly 20 terabytes of data each night, enough to hold the equivalent of four million of your favorite songs, to push our scientific understanding of the structure and evolution of the universe.

Initially called the Large Synoptic Survey Telescope, the Vera C. Rubin Observatory was renamed to honor a pioneer in astronomy, particularly in the field of dark matter, one of the many mysteries the new observatory is expected to help probe. Beginning in the 1960s, Dr. Vera Rubin used a new instrument designed by Kent Ford to study the motion of galaxies. Rubin discovered that the stars in the galaxies she observed orbited faster than expected. One explanation for this discrepancy was that there was more mass in the galaxy than could be seen in the stars alone. Rubins observations helped provide the best observational evidence that the universe is not only composed of ordinary matter, but is actually dominated by dark matter.

In 2019, two U.S. House of Representative members, Eddie Bernice Johnson and Jennifer Gonzlez-Coln, introduced the congressional bill to rename the observatory, the text of which noted Rubins pioneering astronomical work, but also the barriers she faced because of her gender. Princeton University, Rubins preferred choice for graduate work, did not allow women to apply to its programs and the astronomical community largely ignored Rubins research early in her career. Eventually she succeeded in securing a position at the Carnegie Institution of Washington and became the first woman to officially observe at the Palomar Observatory, which was home to the worlds largest telescope. Before her death in 2016, Rubin served as a mentor to other women astronomers and fought for better gender parity in astronomy.

Rubin observed the universe with some of the largest telescopes available during the late twentieth century, including those in Chile, at the newly established Cerro Tololo Inter-American Observatory and the Las Campanas Observatory. When Rubin began her astronomical career, Chile held a small fraction of the worlds telescopes. However, largely due to the nearly perfect dry and clear conditions, particularly in the Atacama Desert in Chiles northern region, today Chile contains the vast majority, around 70%, of the worlds large ground-based telescopes.

Most Chilean observatories constructed in the last 60 years are operated by North American and European nations. For their access to Chiles pristine skies, these international collaborators agreed to reserve 10% of observing time for Chilean astronomers, a percentage that many argue is not adequate. The number of Chilean universities offering PhD degrees in astronomy has increased in the last decade and the number of professional astronomers working in Chile has tripled in that decade alone. At the Vera C. Rubin Observatory, all of the data will be made available to both Chilean and U.S astronomers which should aid the growing number of astronomers in Chile. However, in Chile, women astronomers still only account for 15% of the countrys astronomers, which is about half their representation worldwide. Placing Rubins name on a new observatory and providing greater access to its data is a recognition of her incredible accomplishments and tireless efforts but it is also a reminder of the continued marginalization of women in astronomy and the further inequity across race and nationality.

While the number of women astronomers in Chile remains low, women have succeeded in contributing to the extension of our knowledge of the universe. Dr. Mara Teresa Ruiz broke through her own barriers as she worked to become a trailblazer for women in Chilean astronomy. Born in Santiago, Ruiz was the first woman to earn a degree in the newly formed astronomy program at the University of Chile. When she graduated there were no astronomy PhD granting programs in Chile so she traveled to the United States where she attended Princeton University, the same institution where two decades earlier, Rubin had not been permitted to apply. In 1975, Ruiz became the first woman to earn a PhD in astrophysics at Princeton. Ruiz eventually returned to Chile and helped to rebuild and foster the university system. In 1997, she discovered one of the first free floating brown dwarfs using the European Southern Observatorys La Silla observatory. Brown dwarfs are star-like objects that are too small to fuse hydrogen but too large to be planets. Their discovery and subsequent study refuted the hypothesis that brown dwarfs may account for a significant amount of the dark matter in the universe. For her long and accomplished career in astronomy, Ruiz was awarded Chiles National Prize for Exact Sciences and remains a leader for science in Chile.

Ruiz paved the way for younger scientists to follow in her footsteps. Dr. Brbara Rojas-Ayala began her astronomical studies under Ruiz and continues to research dwarf stars at the University of Tarapac. Dr. Maritza Soto has already impressed with the discovery of three planets, the first of which she discovered in 2011 while a graduate student at the University of Chile. Soto continues her research while hoping to normalize careers in astronomy, particularly for women. In 2019, Soto hoped to import that astronomy is not alien stuff that only two people in the world do; its really a career path. Its something you can do, that anyone can do, if you work a lot for it. Its not impossible, you dont have to be a genius, she says. You can just be a normal person.

By the time the Vera Rubin Observatory begins operations in 2022, followed by other large telescopes built along the Chilean Andes, we can hope that the number of women astronomers using those facilities will continue to rise. To accomplish this, major steps still need to be taken and enforced to make the astronomy community more inviting and more supportive of women, particularly in the places that host the worlds telescopes.

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The Vera C. Rubin Observatory and Women of Chilean Astronomy - National Air and Space Museum

It is no exaggeration to say that the study of extrasolar planets has exploded in recent decades. To date, 4,375 exoplanets have been confirmed in 3,247 systems, with another 5,856 candidates awaiting confirmation. In recent years, exoplanet studies have started to transition from the process of discovery to one of characterization. This process is expected to accelerate once next-generation telescopes become operational.

As a result, astrobiologists are working to create comprehensive lists of potential biosignatures, which refers to chemical compounds and processes that are associated with life (oxygen, carbon dioxide, water, etc.) But according to new research by a team from the Massachusetts Institute of Technology (MIT), another potential biosignature we should be on the lookout for is a hydrocarbon called isoprene (C5H8).

The study that describes their findings, Assessment of Isoprene as a Possible Biosignature Gas in Exoplanets with Anoxic Atmospheres, recently appeared online and has been accepted for publication by the journal Astrobiology. For the sake of their study, the MIT team looked at the growing list of possible biosignatures that astronomers will be on the lookout for in the coming years.

To date, the vast majority of exoplanets have been detected and confirmed using indirect methods. For the most part, astronomers have relied on the Transit Method (Transit Photometry) and the Radial Velocity Method (Doppler Spectroscopy), alone or in combination. Only a few have been detectable using Direct Imaging, which makes it very difficult to characterize exoplanet atmospheres and surfaces.

Only on rare occasions have astronomers been able to obtain spectra that allowed them to determine the chemical composition of that planets atmosphere. This was either the result of light passing through an exoplanets atmosphere as it transitted in front of its star or in the few cases where Direct Imaging occurred and light reflected from the exoplanets atmosphere could be studied.

Much of this has had to do with the limits of our current telescopes, which do not have the necessary resolution to observe smaller, rocky planets that orbit closer to their star. Astronomers and astrobiologists believe that it is these planets that are most likely to be potentially habitable, but any light reflected from their surfaces and atmospheres is overpowered by the light coming from their stars.

However, that will change soon as next-generation instruments like the James Webb Space Telescope (JWST) takes to space. Sara Seager, the Class of 1941 Professor of Physics and Planetary Sciences at MIT, leads the research group responsible (aka. the Seager Group) and was a co-author on the paper. As she told Universe Today via email:

With the upcoming October 2021 launch of the James Webb Space Telescope wewillhave our first capability of searching for biosignature gasesbut it will be tough because the atmospheric signals of small rocky planet are so weakto begin with. With the JWST on thehorizon the number of people working in thefield has growntremendously.Studies such as this one coming up with newpotential biosignature gases, and other workshowing potential false positives even for gases such as oxygen.

Once it is deployed and operational, the JWST will be able to observe our Universe at longer wavelengths (in the near- and mid-infrared range) and with greatly improved sensitivity. The telescope will also rely on a series of spectrographs to obtain composition data, as well as coronagraphs to block out the obscuring light of parent stars. This technology will enable astronomers to characterize the atmospheres of smaller rocky planets.

In turn, this data will allow scientists to place much tighter constraints on an exoplanets habitability and could even lead to the detection of known (and/or potential) biosignatures. As noted, these biosignatures include the chemical indications associated with life and biological process, not to mention the types of conditions that are favorable to it.

These include oxygen gas (O2), which is essential to most forms of life on Earth and is produced by photosynthetic organisms (plants, trees, cyanobacteria, etc.). These same organisms metabolize carbon dioxide (CO2), which oxygen-metabolizing life emits as a waste product. Theres also water (H2O), which is essential to all life as we know it, and methane (CH4), which is emitted by decaying organic matter.

Since volcanic activity is believed to play an important role in planetary habitability, the chemical byproducts associated with volcanism hydrogen sulfide (H2S), sulfur dioxide (SO2), carbon monoxide (CO), hydrogen gas (H2), etc. are also considered biosignatures. To this list, Zhan, Seager, and their colleagues wished to add another possible biosignature isoprene. As Zhan explained to Universe Today via email:

Our research group at MIT focuses on using a holistic approach to explore all possible gases as potential biosignature gas. Our prior work led to the creation of the all small molecules database. We proceed to filter the ASM database to identify the most plausible biosignature gas candidates, one of which is isoprene, using machine learning and data-driven approaches Dr. Zhuchang Zhan.

Like its cousin methane, isoprene is an organic hydrocarbon molecule that is produced as a secondary metabolite by various species here on Earth. In addition to deciduous trees, isoprene is also produced by a diverse array of evolutionary-distant organisms such as bacteria, plants, and animals. As Seager explained, this makes it promising as a potential biosignature:

Isoprene is promising because it is produced in vastqualities by life on Earthas much as methane production!Furthermore, a hugevariety of life forms (from bacteria to plants and animals), those that are evolutionary distant from each other, produce isoprene, suggesting it might be some kind of keybuilding block that life elsewhere might also make.

While isoprene is about as abundant as methane here on Earth, isoprene is destroyed by interaction with oxygen and oxygen-containing radicals. For this reason, Zhang, Seager, and their team chose to focus on anoxic atmospheres. These are environments that are predominantly composed of H2, CO2, and nitrogen gas (N2), which is similar to what Earths primordial atmosphere was composed of.

According to their findings, a primordial planet (where life is beginning to emerge) would have abundant isoprene in its atmosphere. This would have been the case on Earth between 4 and 2.5 billion years ago when single-celled organisms were the only life and photosynthetic cyanobacteria were slowly converting Earths atmosphere into one that was oxygen-rich.

By 2.5 billion years ago, this culminated in the Great Oxygenation Event (GOE), which proved toxic to many organisms (and metabolites like isoprene). It was also during this time that complex lifeforms (eukaryotes and multi-celled organisms) began to emerge. In this respect, isoprene could be used to characterize planets that are in the midst of a major evolutionary shift and laying the groundwork for future animal phyla.

But as Zhang noted, teasing out this potential biosignature will be a challenge, even for the JWST:

The caveats with isoprene as a biomarker are that: 1. 10x-100x the Earths Isoprene production rate is needed for detection; 2. Detecting Near-Infrared isoprene spectral feature can be hindered by the presence of methane or other hydrocarbons. Unique detection of isoprene will be challenging with JWST, as many hydrocarbon molecules share similar spectra features in Near-Infrared wavelengths. But future telescopes that focus on the mid-IR wavelength will be able to detect isoprene spectral features uniquely.

Beyond the JWST, the Nancy Grace Roman Space Telescope (successor to the Hubble mission) will also be taking to space by 2025. This observatory will have the power of One-Hundred Hubbles and its recently-upgraded infrared filters will allow it to characterize exoplanets on its own and through collaborations with the JWST and other great observatories.

There are also several ground-based telescopes currently being built here on Earth that will rely on sophisticated spectrometers, coronographs, and adaptive optics (AOs). These include the Extremely Large Telescope (ELT), the Giant Magellan Telescope (GMT), the Thirty Meter Telescope (TMT) These telescopes will also be able to conduct Direct Imaging studies of exoplanets, and the results are expected to be ground-breaking.

Between improved instruments, rapidly improving data analysis and techniques, and improvements in our methodology, the study of exoplanets is only expected to accelerate further. In addition to having tens of thousands of more available for study (many of which will be rocky and Earth-like), the unprecedented views we will have of them will let us see just how many habitable worlds are out there.

Whether or not this will result in the discovery of extraterrestrial life within our lifetimes remains to be seen. But one thing is clear. In the coming years, when astronomers start combing through all the new data they will have on exoplanet atmospheres, they will have a comprehensive list of biosignatures to guide them.

Seager and Zhans previous work include a concept for a Martian greenhouse that could provide all the necessary food for a crew of four astronauts for up to two years. This greenhouse, known as the Biosphere Engineered Architecture for Viable Extraterrestrial Residence (BEAVER), took second place in the 2019 NASA BIG Idea Challenge. You can read more about it here.

Further Reading: arXiv

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If Astronomers see Isoprene in the Atmosphere of an Alien World, Theres a Good Chance Theres Life There - Universe Today

Galaxy clusters are the largest structures in the universe bound together by gravity. They can contain thousands of galaxies, enormous oceans of hot gas, invisible islands of dark matter and sometimes the glowing ghost of a jellyfish or two.

In the galaxy cluster Abell 2877, located in the southern sky about 300 million light-years from Earth, astronomers have discovered one such jellyfish. Visible only in a narrow band of radio light, the cosmic jelly is more than 1 million light-years wide and includes a large lobe of supercharged plasma, dripping with tentacles of hot gas.

The structure's jelly-like appearance is both "ghostly" and "uncanny," according to the authors of a new paper published March 17 in the Astrophysical Journal. However, even more astonishing than the space jelly's shape is how quickly the structure vanishes from view, the authors said.

Related: 12 Trippy objects hidden in the Zodiac

"This radio jellyfish holds a world record of sorts," lead study author Torrance Hodgson, of the International Centre for Radio Astronomy Research (ICRAR) in Perth, Australia, said in a statement. "Whilst it's bright at regular FM radio frequencies, at 200 megahertz the emission all but disappears. No other extragalactic emission like this has been observed to disappear anywhere near so rapidly."

The universe is swimming with energetic structures that are only visible in radio wavelengths, like the mysterious X-shaped galaxies cartwheeling through space, or the twin blobs at the center of the Milky Way. However, no structure this large has ever been observed in such a narrow band of the radio spectrum.

According to the researchers, that likely means this cosmic jellyfish is actually an odd bird known as a "radio phoenix."

Like the mythical bird that died in flame and rose again from the ashes, a radio phoenix is a cosmic structure that's born from a high-energy explosion (like a black hole outburst), fades over millions of years as the structure expands and its electrons lose energy, then finally gets reenergized by another cosmic cataclysm (such as the collision of two galaxies).

To create a radio phoenix, that last cosmic event must be powerful enough to send shockwaves surging through the dormant cloud of electrons, causing the cloud to compress and the electrons to spark with energy again. According to the study authors, that could cause a structure like the jellyfish cluster to glow brightly in certain radio wavelengths, but dim rapidly in others.

"Our working theory is that around 2 billion years ago, a handful of supermassive black holes from multiple galaxies spewed out powerful jets of plasma," Hodgson said.

That plasma's energy faded over millions of years, until "quite recently, two things happened the plasma started mixing at the same time as very gentle shock waves passed through the system," Hodgson said. "This has briefly reignited the plasma, lighting up the jellyfish and its tentacles for us to see."

The researchers used a computer simulation to show that this explanation is a plausible origin story for that big jellyfish in the sky, though several big questions such as where the "gentle shockwaves" came from remain unanswered. The team hopes to take a closer look at the jellyfish in the future, following the completion of the Square Kilometre Array a network of hundreds of radio telescope antennas planned for construction in the Australian Outback.

Originally published on Live Science.

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Astronomers see a ghostly 'radio jellyfish' rise from the dead in the southern sky - Livescience.com

Two years ago, astronomers managed to photograph a black hole for the very first time. The team behind theEvent Horizon Telescopeproject was awarded the Breakthrough Prizeknown as the Oscars of sciencefor their effort, and New Yorks Museum of Modern Art acquired the image in the form of an inkjet print.

Now, the same astronomers have captured the most detailed photograph to date of a black hole, one of the universes most enigmatic features, which was once thought to be unobservable.

Seen in polarized light, the fuzzy ring of light in the original image is now in focus, with crisp lines swirling in toward the center of what appears to be a bottomless pit, sucking in anything and everything within its grasp.

Its like putting on a pair of polarized sunglasses on a bright sunny dayall of a sudden you can see whats going on, astronomer Sheperd Doeleman of the Harvard-Smithsonian Center for Astrophysics told the New York Times.

The Event Horizon Telescope was designed to capture images of a black hole. The image shows the light around the black holes boundary. Image courtesy of the Event Horizon Telescope.

A black hole is a field of matter so dense that not even rays of light can escape its gravitational pull. But as the black hole inexorably draws in gas, dust, and stars, some light is actually propelled outward in jets of energetic particles.

This jet process is totally amazingsomething the size of our solar system can shoot out a jet that pierces through entire galaxies and even galaxy neighborhoods, Event Horizon Telescope team member Sara Issaoun told IGN.

The new image shows the black holes vortex, and the magnetic field lines at its inner edge, illustrating how the magnetic field both feeds the black holes insatiable hunger and powers the intergalactic fireworks show that surrounds it.

This image shows the jet in the M87 galaxy in polarized light. It is 6,000 light-years long. Image courtesy of ALMA (ESO/NAOJ/NRAO), Goddi et al.

The main finding is that we not only see the magnetic fields near the black hole as expected, but they also appear to be strong. Our results indicate that the magnetic fields can push the gas around and resist being stretched. The result is an interesting clue to how black holes feed on gas and grow,Jason Dexter, a professor at the University of Colorado Boulder, told Space.com.

We are now seeing the next crucial piece of evidence to understand how magnetic fields behave around black holes, and how activity in this very compact region of space can drive powerful jets that extend far beyond the galaxy, said Monika Mocibrodzka, coordinator of the EHT Polarimetry Working Group, in a statement.

The galaxy Messier 87, in the constellation Virgo, as capture by the European Southern Observatorys Very Large Telescope. Photo courtesy of the European Southern Observatory.

The findings from the new image are the subject of three papers published last week in the Astrophysical Journal Letters, two by the Event Horizon Telescope Collaboration and one by lead author Ciriaco Goddi of Radboud University in the Netherlands.

This black hole captured by the telescope lies 55 million light-years away, at the heart Messier 87, a supergiant elliptical galaxy in the constellation Virgo.At 6.5 billion times bigger than our sun, it is unimaginably supermassivethe surrounding circular field of electrified gas or plasma captured in the image measures about 30 billion miles across, or four times Plutos orbit.

The Atacama Large Millimeter/submillimeter Array (ALMA), part of the Event Horizon Telescope Collaboration, set against the Milky Way. Photo by European Southern Observatory Photo Ambassador Babak Tafreshi.

Capturing the image was a global effort. TheEvent Horizon Telescope collaboration is powered by eight ground-based radio telescopes in Chile, Mexico, Spain, Hawaii, Arizona, and the Antarctic, overseen by an international team of radio astronomers thatsynchronize their observations by atomic clock. Together, the sites essentially create a planet-sized telescope.

The projects name comes from the point of no return around a black hole. Beyond the event horizon, no light or matter can escape.

Watch a video approaching the Messier 87 galaxy black hole below.

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Astronomers Have Captured the Most Detailed Photo of a Black Hole EverSee the Magnetic Fields That Power It Here - artnet News

One of the biggest problems is astronomy is a simple one: Not enough light. One of the reasons we make telescopes so big is to collect light to see faint things. The analogy is like a bucket in rain: The wider the bucket the more rain you collect. Photons fall from the sky, and the bigger your mirror the more light you collect.

It's hard to make big telescopes. Supporting a mirror bigger than 8 meters is hard, though making them segmented (like the James Webb Space Telescope) helps. Still, the cost is huge, and to make scopes bigger than what we have now you have to start thinking in the billions of dollars. Ouch.

So astronomers get clever in ways to collect light. One of the most clever astronomers I know is David Kipping. I've written about his work a few times, including about his search for exomoons. Like so many others, he's a photon-starved astronomer, and he recently published an amazing concept to collect more light from cosmic objects: The Terrascope.

It's called that because it uses the Earth as a gigantic lens to focus light.

Yes, seriously. It's the Whole Earth Telescope.

He made a video explaining it:

A lens bends the path light takes (this is called refraction), so that a photon that would otherwise miss your camera gets directed into it. Again with a rain analogy: A raindrop that falls a meter away from you misses you, but if you could deflect (refract!) the path of that drop a little bit while it's still up high, it'll be aimed right at you, and you get wet.

In the case of the Terrascope, the lens is actually Earth's atmosphere. When light moves from one medium to another (like air to water, or space to air), its path bends a little bit. The amount it bends depends on the angle it enters and the stuff (what we usually call the medium) it's passing through. This is why the Sun (and Moon) looks flattened when it sets; the top part of the Sun is passing through less air than the bottom part, and in effect the light from those parts of the Sun get squeezed together, making the Sun look smaller vertically.

So a beam of light coming from a distant star, say, passes through Earth's air and its path bends. The most it bends is about a degree (twice the size of the Sun or Moon in the sky). Now imagine you're floating in space, with the Earth between you and that star. You can't see the star because the Earth is in the way. BUT if you are at just the right distance, the Earth's air will bend the light of the star right at you. The distance from Earth you need to be for this is about 360,000 kilometers, nearly all the way to the Moon.

Now think about this: From there, the Earth looks like a disk, and the air around it a thin ring. Any photon from that star hitting Earth's air at any point in that ring will get bent toward you. All those photons would miss you otherwise, but with Earth's air bending them you see lots of photons. That's exactly how a lens works.

I'll note that the header image of his Twitter account is a fanciful drawing of how this works.

This same effect also creates a phenomenon called a central flash, when an object with an atmosphere passes directly in front of a much more distant object and you get a sudden brightening of light when this eclipse (really, called an occultation) is at its midpoint. It's exactly the same effect I'm talking about here. It's been seen with Neptune's moon Triton blocking a distant star, as well as with Saturn's moon Titan doing the same thing.

So faint stars will appear much brighter because of the extra photons. The light amplification can be huge: For a one-meter telescope, it can be as much as a factor of 80,000! That's incredible. That's 10.5 magnitudes, for those who know their astronomy. A telescope like that could see objects down to Hubble-like faintness even better than Hubble.

It turns out there's a lot of physics involved here, which I've elided over. For example, the air above the Earth gets less dense (and in general colder) with height, and that affects refraction. It depends on the wavelength of light you're looking at as well. And placing a one-meter telescope that far from Earth has other issues, too. The Moon will get close enough that you'll have to do a lot of station keeping every month, for one. Clouds in Earth's atmosphere block light, which is kind of a pain, too, which greatly reduces the light you can see.

Also, you can only look at whatever is behind the Earth, so either you just look at stuff in the sky that happens to be there (and that changes all the time, repeating once a year as the Earth orbits the Sun) or you'll have to move your telescope a loooong way. Kipping goes into some of those problems in his paper.

He finds that a lot of these issues can be overcome simply by moving the telescope farther out. Put it about 1.5 million kilometers from the Earth, and the light that passes about 14 km above Earth's surface gets bent into focus. That avoids clouds, which is great, and most infrared light can pass through the air at that height, allowing that part of the spectrum to be observed as well.

At that distance, a one-meter telescope has the equivalent collecting power of a 150meter telescope! Yegads. That's a lot of light, and the more light you collect from an object the better your data are. Which reminds me: You'll have to block the very bright Earth from your detector as well, but that's something we know how to do (using a coronagraph), and is likely just an engineering problem.

Is a Terrascope actually possible? Well, even Kipping is skeptical in his video and by that I don't mean cynical, I mean scientifically skeptical, being careful to acknowledge the plusses and minuses of the concept. He notes there's a long way to go to figure out all the problems here, but it's very much worth proposing this idea to the community and seeing what happens. And if it does work, it'll be the coolest telescope flying.

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Terrascope: The Whole Earth Telescope - SYFY WIRE

Earths only natural satellite, The Moon, is by far the most romantic and inspiring celestial object in our Solar System. Since the beginning of time, adults and children indistinctively have been lifting their eyes to the sky to gaze at this magnificent celestial body in awe and amazedness.

For millennia, The Moon has sparked the imagination of writers and poets, including James Joyce (What counsel has the hooded moon, Put in thy heart, my shyly sweet, Of Love in ancient plenilune, Glory and stars beneath his feet) or Shakespeare ("th'inconstant moon, That monthly changes in her circled orb"), among many others.

In music, the Moon has captivated the spirit of great artists like The Rolling Stones (Moon Is Up), Pink Floyd (The Dark Side Of the Moon), The Beatles (Mr Moonlight) and The Police (Walking on the Moon). Neil Young, the authors favourite, sings a tribute to his wife, picturing the couple dancing under an Harvest Moon, the closest full Moon to the autumn equinox.

And what better representation than art? For centuries, The Moon has played a central role on the canvases of great painters such as Michelangelo (Creation of the Sun, Moon, and Plants), Edvard Munch (Moon Light), Vincent Van Gogh (White House at Night) and Henri Rousseau (La Encantadora de Serpientes).

But our natural satellite is not only a muse for artists and poets. At an average distance of 384,400 km (238,855 miles), The Moon has a strong impact on our planet. It moderates Earths motion on its axis, which stabilises the climate thus making life possible and favouring agriculture. It also regulates the tides to a rhythm that certain species of crabs, worms and fishes follow for their reproduction.

Sadly, The Moon is constantly shifting away from us at a rate of approximately 3.8 cm (1.5 in) each year, similar to the rate our fingernails grow. But no fear, it will take billions of years before the effects become noticeable.

From Earth, we only see one face of The Moon. This phenomena is called tidal locking, and means that The Moon rotates on its own axis at the same rate that it orbits Earth thus showing us always the same face. A complete orbit around Earth takes 27 days but due to our motion and orbit around the Sun, from our perspective the Moon appears to orbit us every 29 days.

The surface of The Moon is marked by long-inactive volcanoes, impact craters, and lava flows. The areas of the surface that appear bright are called Highlands whereas the dark features are called Marea (from Latin mare: sea). The latter are impact basins that were filled with lava from the volcanoes between 4.2 and 1.5 billion years ago. Some of the Mareas are so marked that are easily visible to the naked eye.

The surface temperature can reach peaks of approximately 130C (265F) when lit by the Sun, then dropping to -170C ( -274F) in darkness. Initial samples returned to Earth from the Apollo missions did not detect any signs of liquid water. In 2008, however, the Indian mission Chandrayaan-1 detected hydroxyl molecules spread across the lunar surface and concentrated at the poles.

Following missions went even further and proved that the surface presents high concentrations of ice water in the permanently shadowed regions of the lunar poles. Finally, in October 2020 NASA confirmed for the first time to have found water also on the sunlit surface of the Moon.

This discovery is of significant importance as it makes the Moon a little more hospitable and simplifies life for NASAs scientists in view of the establishment of a stable colony on our satellite, but also for future missions such as the Artemis Program, which will land the next man and the first woman on the Moon by 2024.

Among other things, the mission will serve as an experiment before sending astronauts to Mars. As a great man once said: That's one small step for a man, one giant leap for mankind.

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Astronomy: The Moon, the most romantic object in the sky - RTL Today

The Deep Space Climate Observatory (DSCOVR) captured a view of the moon as it passed between the spacecraft and Earth. DSCOVR EPIC team

The moon orbits Earth - right? The answer is actually a little more complicated than that.

The moon is circling a point about 3,000 miles from our planet's center, just below its surface. Earth is wobbling around that point, too, making its own circles.

That spot is the Earth-moon system's center of mass, known as the barycenter. It's the point of an object (or system of them) at which it can be balanced perfectly, with the mass distributed evenly on all sides.

The Earth-moon barycenter doesn't line up exactly with our planet's center. Instead, it's "always just below Earth's surface," as James O'Donoghue, a planetary scientist at the Japanese space agency (JAXA), explained on Twitter.

It's hard to imagine what that looks like without seeing it for yourself. So O'Donoghue made an animation to demonstrate what's going on. It shows how Earth and the moon will move over the next three years.

The distance between Earth and the moon is not to scale in the animation, but O'Donoghue used NASA data, so the positions over time are accurate.

"You can pause the animation on the present date to figure out where the Earth and moon physically are right now," O'Donoghue said.

Every planetary system - including the star or planet that appears to be at the center - orbits an invisible point like this one. Our solar system's barycenter is sometimes inside the sun, sometimes outside of it. Barycenters can help astronomers find hidden planets circling other stars: A star's wobbling motion allows scientists to calculate mass they can't see in a given system.

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O'Donoghue made a similar animation of Pluto and its moon, Charon. In this system, the barycenter is always outside of Pluto.

That's because Charon's mass is not that much smaller than Pluto's, so the system's mass is more evenly distributed than Earth and our moon.

Because the barycenter is outside of Pluto, O'Donoghue said, you could actually consider this to be a "double (dwarf-)planet system" rather than a dwarf planet and its moon.

In his free time, O'Donoghue has also made animations to explain why leap years are necessary, why you've probably never seen a model of the solar system to scale, and how incredibly slow the speed of light is.

Read the original article on Business Insider

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An astronomer's animation shows how Earth and the moon both orbit a spot 3,000 miles from the true center of the planet - Yahoo News

This artists impression shows the planet orbiting the Sun-like star HD 85512 in the southern constellation of Vela (The Sail). This planet is one of 16 super-Earths discovered by the HARPS instrument on the 3.6-meter telescope at ESOs La Silla Observatory. This planet is about 3.6 times as massive as the Earth and lies at the edge of the habitable zone around the star, where liquid water, and perhaps even life, could potentially exist. Credit: ESO/M. Kornmesser

Study shows super-Earths are not leftovers of mini-Neptunes, challenging our understanding of planetary formation.

Mini-Neptunes and super-Earths up to four times the size of our own are the most common exoplanets orbiting stars beyond our solar system. Until now, super-Earths were thought to be the rocky cores of mini-Neptunes whose gassy atmospheres were blown away. In a new study published in The Astrophysical Journal, astronomers from McGill University show that some of these exoplanets never had gaseous atmospheres to begin with, shedding new light on their mysterious origins.

From observations, we know about 30 to 50 percent of host stars have super-Earths or mini-Neptunes, and the two populations appear in about equal proportion. But where did they come from?

This artists impression shows the planet orbiting the Sun-like star HD 85512 in the southern constellation of Vela (The Sail). This planet is one of 16 super-Earths discovered by the HARPS instrument on the 3.6-meter telescope at ESOs La Silla Observatory. This planet is about 3.6 times as massive as the Earth and lies at the edge of the habitable zone around the star, where liquid water, and perhaps even life, could potentially exist. Credit: ESO/M. Kornmesser

One theory is that most exoplanets are born as mini-Neptunes but some are stripped of their gas shells by radiation from host stars, leaving behind only a dense, rocky core. This theory predicts that our Galaxy has very few Earth-sized and smaller exoplanets known as Earths and mini-Earths. However, recent observations show this may not be the case.

To find out more, the astronomers used a simulation to track the evolution of these mysterious exoplanets. The model used thermodynamic calculations based on how massive their rocky cores are, how far they are from their host stars, and how hot the surrounding gas is.

Contrary to previous theories, our study shows that some exoplanets can never build gaseous atmospheres to begin with, says co-author Eve Lee, Assistant Professor in the Department of Physics at McGill University and the McGill Space Institute.

The findings suggest that not all super-Earths are remnants of mini-Neptunes. Rather, the exoplanets were formed by a single distribution of rocks, born in a spinning disk of gas and dust around host stars. Some of the rocks grew gas shells, while others emerged and remained rocky super-Earths, she says.

Planets are thought to form in a spinning disk of gas and dust around stars. Rocks larger than the moon have enough gravitational pull to attract surrounding gas to form a shell around its core. Over time this shell of gas cools down and shrinks, creating space for more surrounding gas to be pulled in, and causing the exoplanet to grow. Once the entire shell cools down to the same temperature as the surrounding nebular gas, the shell can no longer shrink and growth stops.

For smaller cores, this shell is tiny, so they remain rocky exoplanets. The distinction between super-Earths and mini-Neptunes comes about from the ability of these rocks to grow and retain gas shells.

Our findings help explain the origin of the two populations of exoplanets, and perhaps their prevalence, says Lee. Using the theory proposed in the study, we could eventually decipher how common rocky exoplanets like Earths and mini-Earths may be.

Reference: Primordial Radius Gap and Potentially Broad Core Mass Distributions of Super-Earths and Sub-Neptunes by Eve J. Lee and Nicholas J. Connors, 10 February 2021, The Astrophysical Journal.DOI: 10.3847/1538-4357/abd6c7

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Mysterious Origins of Super-Earths Uncovered by Astronomers - SciTechDaily

View at EarthSky Community Photos. | Michael Zuber caught the bright planets Jupiter and Saturn above the building in this photo near the starry band of the Milky Way, from Terlingua, Texas, on November 11, 2020. Thank you, Michael.

Do you think of the Milky Way as a starry band across a dark night sky? Or do you think of it as a great spiral galaxy in space? Both are correct. Both refer to our home galaxy, our local island in the vast ocean of the universe, composed of hundreds of billions of stars, one of which is our sun.

Long ago, it was possible for everybody in the world to see a dark, star-strewn sky when they looked heavenward at night, rather than the obscuring glow of city lights. In those ancient times, humans looked to the starry sky and saw a ghostly band of light arcing across the heavens, from horizon to horizon. This graceful arc of light moved across the sky with the seasons. The most casual sky-watchers could notice that parts of the band are obscured by darkness, which we now know to be vast clouds of dust.

EarthSky lunar calendars are back in stock! A few left. Get one while you can!

Myths and legends grew up in different cultures around this mysterious apparition in the heavens. Each culture explained this band of light in the sky according to its own beliefs. To the ancient Armenians, it was straw strewn across the sky by the god Vahagn. In eastern Asia, it was the Silvery River of Heaven. The Finns and Estonians saw it as the Pathway of the Birds. Meanwhile, because western culture had become dominated by the legends and myths of first the ancient Greeks and then the Romans, it was their interpretations which were passed down to a majority of languages. Both the Greeks and the Romans saw the starry band as a river of milk. The Greek myth said it was milk from the breast of the goddess Hera, divine wife of Zeus. The Romans saw the river of light as milk from their goddess Ops.

Thus it was bequeathed the name by which, today, we know that ghostly arc stretching across the sky: the Milky Way.

View at EarthSky Community Photos. | William Mathe captured this image on August 15, 2020, and wrote: Hiked up to the top of Rocky Mountain National Park in Colorado just below 12,000 feet. Was greeted with a raging forest fire about 10 miles to the west hung around long enough to get a couple of snaps of the Milky Way. You can see the brown clouds of smoke hanging in the valley below the rock outcrop on which I was perched. Thank you, William.

When you are standing under a completely dark, starry sky, away from light pollution, the Milky Way appears like a cloud across the cosmos. But that cloud betrays no clue as to what it actually is.Until the invention of the telescope, no human could have known the nature of the Milky Way.

Just point even a small telescope anywhere along its length and you will be rewarded with a beautiful sight. What appears as a cloud to the unaided eye resolves into countless millions of stars, whose distance and close relative proximity to each other do not permit us to pick them out individually with just our eyes. In the same way, a raincloud looks solid in the sky but is made up of countless water droplets. The stars of the Milky Way merge together into a single band of light. But through a telescope, we see the Milky Way for what it truly is: a spiral arm of our galaxy.

We cant get outside the Milky Way, so we have to rely on artists concepts, like this one, to show us how it might look. The larger orange/yellow blob in the lower part of the image is a massively glorified representation of our sun, showing its approximate location with respect to the center. Image via ESA.

Thus we arrive at the second answer to the question of what the Milky Way is. To astronomers, it is the name given to the entire galaxy we live in, not just the part of it we see in the sky above us as that river of light. If this seems confusing, we must acknowledge the need for our galaxy to have a name. Many other galaxies are designated by catalogue numbers rather than names, for example the New General Catalogue, first published in 1888, which merely assigns a sequential number to each. More recent catalog numbers contain information of far more use to astronomers, for example the galaxys location on the sky and during which survey it was discovered. Moreover, a galaxy may appear in more than one catalog and thus possess more than one designation. For example,the galaxy NGC 2470 is also known as 2MFGC 6271.

These galaxy designations are certainly unromantic, belying the dazzling beauty of the objects they are attached to. But other galaxies, particularly those brighter, closer galaxies which appear as more than just fuzzy smudges of light in a telescope, were given names by astronomers of the 17th and 18th centuries according to their appearance: the Pinwheel, the Sombrero, the Sunflower, the Cartwheel, the cigar and so forth. These names were attached to galaxies long before there were any systematic sky surveys that made it necessary to use numerical labeling systems, due to the sheer number of galaxies the surveys discovered. In time, the galaxies bearing these descriptive labels were incorporated into various catalogs, but many are still known by their names. Our own galaxy does not appear in any index of galaxies. There was, however, a need for a name to refer to it by. Thus we call it The Milky Way instead of the galaxy or our galaxy. So that name refers to both that river of light across the sky, which is part of our galaxy, and the galaxy as a whole. When not using the name, astronomers refer to it with a capital G (the Galaxy), and all other galaxies with a lowercase g.

In this artists conception of the Milky Way, the suns location is shown below the central bar, at the inward side of the Orion Arm (called by its slightly dated name, the Orion Spur). The Orion Arm lies between the Sagittarius Arm and the Perseus Arm. Image via NASA/ JPL/ ESO/ R. Hurt/ Wikimedia Commons.

Our solar system is located about 2/3 of the way out from the Galactic Center toward the edge of the galaxy. We are, in fact, 26,000 light years from the center, or 153,000 trillionmiles (246,000 trillion km). Under the stars we can look toward the middle of the galaxy or we can look in the other direction, out toward the edge. When we look to the edge, we see a spiral arm of the Milky Way known as the Orion-Cygnus Arm (or the Orion spur): a river of light across the sky that gave rise to so many ancient myths. The solar system is just on the inner edge of this spiral arm. If we look in the other direction, one would naturally expect to be able to see the center of the galaxy, which is located in the constellation of Sagittarius. But unfortunately, we cannot see it. The Galactic Center is hidden from us behind vast clouds of dark gas that telescopes operating in visible light cannot see through. It is only in recent decades that astronomers have been able to pierce that dusty fog with infrared telescopes to reveal what, throughout human history, has been concealed. With these new additions to astronomers arsenal of instruments, the study of around 100 stars at the galactic center revealed that those giant clouds of dark dust were hiding a monster: a black hole, designated Sagittarius A*, with a mass four million times the mass of our sun.

The Milky Way as seen in different lights, that is, different wavelengths of light. The most familiar view is the one seen in optical light, which is the 3rd image from the bottom. Here, most of the galaxy is obscured by gas clouds (dark areas). But look in the same direction in infrared light, and you can see through the clouds (4th, 5th and 6th image from the bottom)! Read more about these images. Image via NASA.

Our Milky Way galaxy is one of billions in the universe. We do not know exactly how many galaxies exist: a modern estimate vastly increases previous counts to as many as 2 trillion. The Milky Way is approximately 100,000 light-years across, or 600,000 trillion miles (950,000 trillion km). We do not know its exact age, but we assume it came into being in the very early universe along with most other galaxies: within perhaps a billion years after the Big Bang. Estimates of how many stars live within the Milky Way vary quite considerably, but it seems to be somewhere between 100 billion and double that figure. Why is there so much variance? Simply because it is so difficult to count the number of stars in the galaxy from our vantage point here on Earth. Imagine being in a crowded room full of people and trying to count them without being able to move around the room. From where you are standing, all you can do is make an estimate because those people farther away from you are hidden by those closer. Neither can you even see what size and shape the room is; its walls are hidden from you by the mass of people. Its exactly the same from our position in the galaxy.

It is this inability to see the structure of the Milky Way from our location inside it that meant for most of human history we did not even recognise that we live inside a galaxy in the first place. Indeed, we did not even realise what a galaxy is:a vast city of stars, separated from others by even vaster distances. Without telescopes, most of the other galaxies in the sky were invisible. The unaided eye can only see three of them: from the Northern Hemisphere we can see only the Andromeda galaxy, also known as M31, which lies some two million light-years from us and which is in fact the farthest object we can see with our eyes alone, under dark skies. The skies in the Southern Hemisphere have the Small and Large Magellanic Clouds, two amorphous dwarf galaxies orbiting our own. They are far larger and brighter in the sky than M31 simply because they are much closer.

The Andromeda Galaxy (M31) is the closest large galaxy to our Milky Way. Its seen here with two satellite galaxies: M32 is the compact fuzzy object located to the right of the Andromeda Galaxys center, and M110 is the more extended nebulous object at the top left of the central galaxys nucleus. Image via Zolt Levay/ Flickr.

The Large and Small Magellanic Clouds over Paranal in Chile. These are satellite galaxies of the Milky Way and are only visible from the Southern Hemisphere. Image via the European Southern Observatory.

Until the 1910s, the existence of other galaxies had not been observationally confirmed. Those fuzzy patches of light astronomers saw through their telescopes were long believed to be nebulae, vast clouds of gas and dust close to us, and not other galaxies. But the concept of other galaxies was born earlier, in the early and mid-18th century, by Swedish philosopher and scientist Emanuel Swedenborg and English astronomer Thomas Wright, who apparently conceived the idea independently of each other. Building upon the work of Wright, German philosopher Immanuel Kant referred to galaxies as island universes. The first observational evidence came in 1912 by American astronomer Vesto Slipher, who found that the spectra of the nebulae he measured were redshifted and thus much further away than previously thought.

And then, Edwin Hubble, through years of painstaking work at the Mount Wilson Observatory in California, confirmed in the 1920s that we do not live in a unique location: our galaxy is just one of perhaps trillions. Hubble came to this realization by studying a type of star known as a Cepheid variable, which pulsates with a regular periodicity. The intrinsic brightness of a Cepheid variable is directly related to its pulsation period: by measuring how long it takes for the star to brighten, fade and brighten again you can calculate how bright it is, that is to say, how much light it emits. Consequently, by observing how bright it appears from the Earth you can calculate its distance, in the same way that seeing distant car headlights at night can tell you how far away the car is from how bright its lights appear to you. You can judge the distance of the car because you know all car headlights have about the same brightness.

An example of a Cepheid Variable star is RS Puppis. It varies in brightness by almost a factor of 5 every 40 days. Image via NASA/ ESA/ Wikimedia Commons.

One of Edwin Hubbles great achievements was finding Cepheid variables in M31, the Andromeda galaxy. Hunched under the eyepiece of the huge Hooker Telescope in the cold night air, Hubble repeatedly photographed it, eventually finding what he was seeking in that distant spiral: stars which changed in brightness over a regular period. Performing the calculations, Hubble realised that M31 is not astronomically close to us at all. It is 2 million light years away. It is a galaxy like our own, long thought to be a third as big again as the Milky Way but which is now believed to be about the same size.

Hubble, for whom this discovery must have been a monumental shock, surmised that our galaxy was no different from M31 and the others he observed, thus relegating us to a position of lesser importance in the universe. This was as big a revelation and diminution of our position in the universeas when humans came to understand that the Earth is not the center of the universe: that we, along with the other planets we see, orbit the sun. We do not live in a special or privileged location. The universe does nothave any vantage points which are superior to others. Wherever you are in the universe and you look up at the stars, you will see the same thing. Your constellations may be different, but no matter in which direction you look, you see galaxies rushing away from you in all directions as the universe expands, carrying the galaxies along with it. Until the work by Slipher and Hubble (and others), we did not know the universe was expanding and it took a surprisingly long time for this fact to be accepted by the astronomical community. Even Albert Einstein did not believe it, introducing an arbitrary correction into his Relativity calculations which would result in a static, non-expanding universe. However, Einstein later called this correction the greatest error in his career when he finally accepted that the universe is expanding.

Although Hubble showed us that ours is just one galaxy among perhaps trillions, this did not tell astronomers what the Milky Way would look like it if you were to see it from outside. We knew it has spiral arms: that band of light across the sky was clear evidence of that. But as to how many spiral arms there are, or how big the galaxy is, or how many stars inhabit it, those were questions still unanswered in the 1920s. It took most of the 20th century after Hubbles discoveries to piece together the answers to these questions, through a combination of painstaking work with both Earth- and space-based telescopes. So if one could travel outside our galaxy, what would it look like? A standard analogy compares it to two fried eggs stuck together back-to-back. The yolk of the egg is known as the Galactic Bulge, a huge globe of stars at the center extending above and below the plane of the galaxy. The Milky Way is now thought to have four spiral arms winding out from its center like the arms of a Catherine wheel. But these arms do not actually meet at the center: a few years ago astronomers discovered that the Milky Way is in fact a barred spiral galaxy, having a bar of stars running across its center, from which the spiral arms extend at either end. Barred spiral galaxies are not uncommon in the universe, so our galaxy is certainly nothing out of the ordinary. We do not yet, however, understand how that central bar forms.

This Hubble image shows galaxy NGC 7773, an example of a barred spiral galaxy thought to be similar to the Milky Way. Its bulge is stretched out into a bar-shaped structure, extending to the inner parts of the galaxys spiral arms. Astronomers believe a bar in the center of a galaxy is a sign of galaxy maturity. Younger spiral galaxies do not feature barred central structures as often as older spirals do. Image via ESA/Hubble, CC BY 4.0, Creative Commons

Only two years ago, another major discovery was made: the Milky Way is not a flat disk of stars but has a kink running across it like an extended S. Something has warped the disk. At the moment the finger points at the gravitational influence of the astronomically-close Sagittarius dwarf galaxy, one of perhaps twenty small galaxies that orbit the Milky Way, like moths around a flame. As the Sagittarius galaxy slowly orbits around us, its gravity has pulled on our galaxys stars, eventually creating the warp.

These dwarf galaxies are not the only astronomical objects bound to our own. The Milky Way is surrounded by a halo of globular clusters, concentrations of stars looking like fuzzy golf balls, containing perhaps a million or so extremely ancient stars.

It is highly probable that we will continue to make more landmark discoveries about the Milky Way. The study of its nature and origin is accelerating as new astronomical tools become available, such as the European Space Agencys orbiting Gaia telescope, which is making a three-dimensional map of our galaxys stars with exquisite and quite unprecedented accuracy: it aims to map a billion of them. Gaias data allows astronomers to see where the stars are, in which direction they are moving and how fast. This incredible map is already revealing previously-unknown features of our galaxy: the discovery of the galaxys warp by Gaia is one such feature. It is an extremely exciting time for the study of our galaxy, and the discoveries being made are telling us so much about not just our own galaxy but other spiral galaxies as well.

A composite image of the orbiting telescope Gaia, mapping the stars of the Milky Way. Image via ESA.

It is all a far cry from when, thousands of years ago, our ancestors ascribed fantastic beasts and gods to that mysterious band of light they saw as they stood in awe under the starry sky.

Bottom line: Our galaxy, the Milky Way, is a lot more than we can see from Earth without instruments. Here, we look into the origin of the name, the structure, and the fascinating history of how our knowledge of our own galaxy has developed over the centuries and continues to develop today.

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What is the Milky Way? | Astronomy Essentials - EarthSky

If theres one thing Black people have mastered, it is resilience. Throughout history, our people have found ways to make the best out of situations. Weve managed to educate and enlighten through jokes, while simultaneously using entertainment as an escape from the sometimes painful reality of being Black. Whether its beautifully painted or holds a hurtful truth, Black peoples ability to express Black joy has been one of the strongest forms of overcoming.

This week, as we highlight another groundbreaking Black entity for Black History Month, we have to bring attention to the Astronomy Club. Founded in New York in 2014, the all-Black improv comedy group has made a name for itself on stage and television. Each person in the collective has talents that spread beyond the group, but they come together to create stories larger than life, and funnier than most.

Astronomy Club arrived at a time when Black sketch shows really made a come up. They offered a different approach with a wide range of topics. They gave light, laughter and used their own confidence to put themselves into new rooms. They created a world fit for them a world that different types of Black people could find themselves and find joy within. The group was created with the for us, by us mentality.

Without further ado, here are seven reasons why the collective deserves its flowers.

1. Black and Proud

Astronomy Club is composed of eight Black improvisers: Shawtane Bowen, Jonathan Braylock, Ray Cordova, James III, Caroline Martin, Jerah Milligan, Monique Moses, and Keisha Zollar. The crew tells stories from the average Black persons gaze with topics that range from the entertainment industry, race relations, and the overall Black experience leaving audiences with a message each time.

2. From Theater to TV

After finding each other and working within their unique chemistry, Milligan and James III wanted to give sketch comedy a shot. This decision became one of their defining moments. In 2013, they wrote their first sketch during Black History Month that ran for an entire year at the theater. The same show made it to the New York Comedy Festival where Comedy Central named Astronomy Club comics to watch in 2016. Two years later, the network dropped the collectives digital series in 2018. The following year, Netflix picked up the show for one hilarious season.

3. First of Many

Astronomy Club has already made a name for itself. It is known to be the first all-Black house team at the Upright Citizen Brigade Theater in New York. On the flip side, though the groups series only aired one season on Netflix, the shows reviews were nearly 100 percent in favor of its sketches.

4. Breaking the Mold

A major theme of the show is capturing moments from their podcast and turning them into real, yet funny life. They use their sketches often to tell stories that break away from the usual stereotypes Black people face. In an interview, Braylock shared that the team felt freedom being able to create alternative worlds and realities. In an industry dominated by the white counterparts, the team basked in their moment and did what needed to be done with each episode.

5. Power of Laughter

As stated before, Black joy is one of the strongest forms of resistance. With each decade, struggles arise and Black people can fight the pain through laughter. Astronomy Clubs main tool is comedy fits perfectly into the narrative. Scenarios that might otherwise disturb the community can now make thousands laugh, while at the same time educate.

6. Fighter Spirit

When Astronomy Clubs series was not renewed on Netflix for a second season, the cast took the news with grace. At the same time, they made sure to bring awareness to the lackluster job the streaming service did of providing users with access and information regarding their show. Feeling slighted, the cast was vocal about their issues. Fans even created petitions to get it back, but their efforts fell short. Netflix pulled the plug but the cast didnt back down.

7. Inspire Resilience

In true form, Astronomy Club sends a message to all to keep going. In many ways, their own personal story tells one of faith. With their sketches, Astronomy Club vowed to never make Black people the butt of their jokes. They showed respect to our history and, at times, created a reality that is one of hope. Their ability to twist the narrative, to be creative, to inspire other comedians, and to enjoy themselves is a nod to the nature of resilience we carry as a community.

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7 reasons Astronomy Club deserves its flowers for being the future of comedy - REVOLT TV

Astronomers discovered that extreme tidal loss may be a possible explanation for why some galaxies seem to have no dark matter, a mystery type of matter that's supposed to take up to 27 percent of the universe, according to NASA. Dark energy takes up another 68 percent, creating a repulsive force that speeds up the universe's expansion. Neither has been directly seen so far but rather inferred through their effects on space.

The team from the University of California, Riverside, found anomalies in some smaller galaxies, known as "dwarf galaxies" (containing up to a billion stars, compared to the Milky Way's 200-400 billion). Some appear to have no dark matter at all. This is despite the fact that they were formed in galaxies that were teeming with dark matter previously. What is the explanation for this phenomenon, which muddies our understanding of dark matter?

The scientists used a cosmological simulation called Illustris on dark-matter-free galaxies DF2 and DF4. They wanted to understand how similar space objects would evolve and what might have happened that led them to lose dark matter. The simulation could create galaxies, with evolving stars, supernovas, and growing and merging black holes. Within the simulation, the researchers found "dwarf galaxies" similar to DF2 and DF4 which lost over 90 percent of their dark matter through the process of tidal stripping, in which material is stripped from the galaxy by galactic tidal forces.

The study's first author was the physics and astronomy graduate student Jessica Doppel, while the co-author Laura Sales, an associate professor of physics and astronomy, was Doppel's graduate advisor.

"Interestingly, the same mechanism of tidal stripping is able to explain other properties of dwarfs like DF2 and DF4 for example, the fact that they are 'ultradiffuse' galaxies," said Sales. "Our simulations suggest a combined solution to both the structure of these dwarfs and their low dark matter content. Possibly, extreme tidal mass loss in otherwise normal dwarf galaxies is how ultradiffuse objects are formed."

Besides Sales and Doppel, the study involved Julio F. Navarro from the University of Victoria in Canada, Mario G. Abadi and Felipe Ramos-Almendares of the National University of Crdoba in Argentina, Eric W. Peng of Peking University in China, and Elisa Toloba of the University of the Pacific in California.

Laura Sales (seated, left) and her research group of students, including Jessica Doppel (seated, right).

Credit: UCR/Stan Lim

Sales's team is currently collaborating with the Max Planck Institute for Astrophysics in Germany to improve the simulations with more advanced physics and a resolution that's 16 times better than the Illustris they used on this study.

Check out the new paper, published in the Monthly Notices of the Royal Astronomical Society.

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Astronomers figure out why some galaxies are missing dark matter - Big Think

Different Visions

Origins of a Perennial Bouquet, an exhibition curated by Bose Krishnamachari features works that reflect a range of material, artisanship and workmanship. Among the featured artists is Benitha Perciyal, whose practice encapsulates the use of primarily organic materials, with a strong focus on those that induce olfactory experiences such as myrrh, cinnamon and frankincense; Tanya Goel, who focuses on textured pigments though she uses a diverse array of materials from urban climes such as aluminum, concrete, glass, soil and mica to accentuate the equally versatile effect of light on them; Manish Nai, who is set apart by his thrust on minimalism at a time where excessive ornamentation is the norm; and Sumedh Rajendran, in whose works one finds contradictory values and social apathy juxtaposed. At Vida Heydari Contemporary Art Gallery till February 28.

Space and Beyond

Bhandarkar Oriental Research Institute and Jyotirvidya Parisanstha have launched a course on astronomy in ancient India. The topics include Introduction to astronomical concepts, Indian Time Measurement Systems, Indian Astronomers, Ancient Indian Concepts about Astral Bodies, Planetary Motion and Space, Instruments and Observatories and Archeo-Astronomy. A batch in Marathi begins on February 15. The course will be held till February 20, 8 pm-9.30 pm. Entry: Rs 1,000. Registration Link https://forms.gle/omCeH9Dcf9HqzASs7

Light and Shadow

A performance, titled Tholu Bommalata, brings the traditional shadow theater tradition of Andhra Pradesh to an online performance. Tholu Bommalata refer to puppets created from goat and sheep skin and designed and painted by artisans. They appear on stage, behind a white curtain, and the audience can only view the coloured shadows, but not the actual puppets, by means of a light source. In the performance, painting, music, dance, engraving, acting and narrative storytelling come together in a riveting entertainer. On BookMyShow on February 15 onward. Charges: Rs 30. Click onhttps://in.bookmyshow.com/plays/tholu-bommalata/ET00305516

Things of Beauty

A workshop on making jewellery from resin not only takes you through the process but also ensures you go home with six works you have created, from neckpieces to earrings to finger rings. At Studio Artzone on February 16 and 17, 11 am-2 pm. Entry: Rs 1,500. Contact: 9822254472

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Pune, this week: From an art exhibition to an astronomy course and a lot more - The Indian Express

Material accelerating away from the site of a stellar explosion has been discovered in a star-forming cloud.

It's only the second time molecular outflows of this kind have ever been clearly seen, but it could help astronomers understand how the most massive stars get their start in life.

In the 1980s, astronomers discovered something peculiar in the star-forming Orion nebula: streamers of dense molecular gas, travelling at speed through space. When these streamers were mapped, they seemed to originate from a single point.

Since then, molecular outflows have been discovered in many star-forming regions. They are thought to play an important role in the formation of low-mass stars, transporting away the excess angular momentum that would otherwise cause baby stars to spin themselves into oblivion.

The Orion outflow, however, was one of a kind. Molecular outflows in low-mass stars are bipolar; that is, there are only two of them, shooting out in opposite directions. The outflows in Orion were much more numerous and they were also found in a region where much more massive stars - over 10 times the mass of the Sun - are forming.

Combined X-ray, radio and optical image of W28, the region's parent complex. (NASA/ROSAT; NOAO/CTIO/P.F. Winkler et al; NSF/NRAO/VLA/G. Dubner et al.)

Now, we don't know as much about the formation of massive stars as we do about the smaller ones. Massive stellar nurseries are rarer and tend to be more distant, making them harder to see. So astronomers thought that maybe the Orion outflows could yield some clues.

Yet there was nothing at the source of the outflows - no baby massive star. This could imply several explosive scenarios, such as a merger between two massive baby stars, or gravitational energy liberated by the formation of a nearby massive binary. But with only one observation of its kind, it's difficult to make a firm ruling.

To try and learn more about this phenomenon, a team of astronomers led by Luis Zapata of the National Autonomous University of Mexico decided to turn one of our most powerful radio telescopes, the Atacama Large Millimeter/submillimeter Array (ALMA), at a known massive stellar nursery.

False-colour image of W28. (NRAO/AUI/NSF and Brogan et al.)

G5.890.39, also known as W28 A2, is around 9,752 light-years away. It contains a bright, expanding shell-like ultra-compact hydrogen cloud and powerful molecular outflows. Zapata and his team had previously noted that six of these filaments seemed to point directly at the centre of the hydrogen cloud, but their results were inconclusive.

ALMA cleared that ambiguity right up. It detected dense streamers based on the millimetre-wavelength emission from carbon dioxide and silicon monoxide.

(Zapata et al., ApJL, 2020)

The astronomers were able to identify 34 molecular streamers zooming radially away from the heart of the cloud, accelerating outwards. Based on their velocities of up to 130 kilometres (80 miles) per second, the outflows are about 1,000 years old; whatever explosion produced them occurred about a millennium ago.

They are not as powerful as the outflows you'd expect from a supernova explosion, which occurs when a massive star dies. In addition, as was also seen in the case of Orion, there was no star in the centre - just a region of ionised gas, possibly the result of heating during an explosive event.

If there was a star (or multiple stars) associated with the event that produced the outflows, it could have been ejected from the region.

Because massive stars always form in clusters, such interactions are possibly quite common, which in turn could shed some light on massive star formation. If two protostars merged, they would likely have ended up as one much larger star.

Based on the Orion outflows, the G5.89 outflows, and the marginal detection of what could be similar outflows in a star-forming region known as DR-21, the team estimates that these events occur every 130 years or so. That's very close to an estimated rate of supernova explosions.

The unpredictability of these events, and the short duration of the outflow phase, may make them pretty hard to find; but, now that we know what to look for and how, astronomers may be able to build a catalogue of these kinds of events. In turn, that will help us understand why they occur.

"If enough of these outflows can be detected in the future, the merging of clusters of stars may be an important formation mechanism of massive stars," Zapata said.

The research has been published in The Astrophysical Journal Letters.

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Astronomers Mapped The Spectacular Accelerating Outflows of a Stellar Explosion - ScienceAlert

A plot showing the relationship between the clustered orbits of several Trans-Neptunian Objects, or TNOs, in the extreme outer solar system as a result of gravitational interactions with an unseen world dubbed Planet 9. Image: Caltech/R. Hurt (IPAC)

For the past several years, astronomers have been searching for an unseen planet beyond the orbit of Pluto, a presumed world with 10 times the mass of Earth that could be responsible for the seemingly clustered orbits of small Trans-Neptunian Objects, or TNOs, in the extreme outer solar system. So far, Planet 9 has eluded detection.

Dealing a possible blow to the theorised planet, a team of researchers led by Kevin Napier of the University of Michigan suggests selection bias may have played a role in the original justification for Planet 9.

TNOs are so distant and dim they can only be detected, if seen at all, when their orbits carry them relatively close to the inner solar system. Napiers team analysed 14 other extreme TNOs discovered in three surveys and concluded their detection was based on where they happened to be at the time and the ability of the telescopes in question to detect them.

In other words, the clustering seen in the orbits of the original TNOs cited in support of Planet 9 may have been the result of where the bodies happened to be when they were observed. TNOs may well be uniformly distributed across the outer solar system without any need for the gravitational influence of an unseen planet.

It is important to note that our work does not explicitly rule out Planet X/Planet 9; its dynamical effects are not yet well enough defined to falsify its existence with current data, the researchers write in a paper posted on ArXiv. Instead, we have shown that given the current set of ETNOs (extreme TNOs) from well-characterised surveys, there is no evidence to rule out the null hypothesis.

Mike Brown and Konstantin Batygin at the California Institute of Technology, the original proponents of Planet Nine, beg to differ.

Can their analysis distinguish between a clustered and uniform distribution, and the answer appears to be no, Batygin said in an update posted by the journal Science.

Brown took to Twitter on 16 February to voice his thoughts, showing diagrams of the TNOs that he says support the original case for Planet 9. And in a blog post, he provided a detailed rebuttal, concluding that in the end, the previously measured clustering from our 2019 paper is still valid and the conclusions of that paper remain.

The clustering of distant Kuiper belt objects is highly significant, Brown writes. Its hard to imagine a process other than Planet Nine that could make these patterns. The search continues.

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The case for, and against, the still-unseen Planet 9 Astronomy Now - Astronomy Now Online

A graphic representation of the scale of the solar system shows Earths position, 93 million miles from the Sun, or one astronomical unit, at the extreme left. A body nicknamed Farfarout is at the far right end of the scale, currently 132 times farther from Sun than Earth. Pluto is just to the left of the 40 AU marker. Image: Roberto Molar Candanosa, Scott S. Sheppard from Carnegie Institution for Science, and Brooks Bays from University of Hawaii.

Extended tracking has allowed astronomers to pin down the orbit of a presumed dwarf planet in the extreme outer solar system that takes a thousand years to complete one trip around the Sun. Knicknamed Farfarout, the frigid body is the most distant solar system object yet detected, eclipsing the previous record holder, Farout.

Listed as 2018 AG37 by the Minor Planet Center, Farfarout is currently 132 times farther from the Sun than Earth (132 astronomical units, or AU) and nearly four times more distant than Pluto. Its highly elongated trajectory carries it inside the orbit of Neptune and as far as 175 AU from the Sun. Analysis indicates the object is about 250 miles across, putting in on the low end of the dwarf planet scale (assuming it is an icy body).

A single orbit of Farfarout around the Sun takes a millennium, said University of Hawaii researcher David Tholen, a member of the team that discovered the body in 2018. Because of this long orbital period, it moves very slowly across the sky, requiring several years of observations to precisely determine its trajectory.

Tholen, Scott Sheppard of the Carnegie Institution for Science and Chad Trujillo of Northern Arizona University lead an ongoing survey to map the outer solar system beyond Pluto. They discovered the previous record holder, Farout, which is 120 AU from the sun.

The discovery of the even more distant Farfarout demonstrates our increasing ability to map the outer solar system and observe farther and farther towards the fringes of our solar system, said Sheppard. Only with the advancements in the last few years of large digital cameras on very large telescopes has it been possible to efficiently discover very distant objects like Farfarout.

Farfarout will be given an official name after its orbit is known with greater precision. In the meantime, Sheppard described Farfarout as just the tip of the iceberg of objects in the very distant solar system.

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'Farfarout' confirmed to be really, seriously far out Astronomy Now - Astronomy Now Online