Astro Blog

By Daniel Clery , Science.  Excerpt: Astronomers have discovered more than 6000 planets orbiting other stars—many of them small and rocky like Earth. But despite years of searching, firm evidence that such worlds have stable atmospheres has remained elusive. Now, researchers report in Science that the relatively nearby super-Earth LHS 1140b appears to be leaking helium gas into space , implying it still has a substantial atmosphere billions of years after its birth. ...Many teams are zooming in on LHS 1140b, because of its many charms. Besides being nearby, it could be hiding other gases in its lower atmosphere, such as nitrogen and carbon dioxide—much like Earth. And if those gases provide an element of greenhouse warming, it could possess a liquid water ocean warm enough to swim in....  Full article at https://www.science.org/content/article/astronomers-spot-first-atmosphere-around-potentially-habitable-alien-world .  See also New York Times article, Astronomers Find a...

By ScienceAdvisor.  Excerpt: Most small worlds in the outer Solar System are not expected to have atmospheres. Gas escapes too easily, and there is little to replace it. Pluto, larger and rich in ices that can vaporize into gas, has long been the only known exception. Now,  astronomers have spotted a thin atmosphere around a much smaller object . Known as 2002 XV93, it’s a distant plutino, a Kuiper Belt object ...described in a new paper in  Nature Astronomy . At roughly 250 kilometers in radius, it falls far below the size thought necessary to sustain an atmosphere. But in January 2024, as the object passed in front of a distant star, astronomers noticed something unusual: The starlight did not vanish all at once, but instead dimmed gradually. That subtle fade is the telltale signature of an atmosphere. ...By modeling the signal, researchers estimated a surface pressure of about 100 to 200 nanobars, tens of times thinner than Pluto’s atmosphere, but far denser than expec...

By Benjamin Thompson  &  Nick Petrić Howe , Nature.  Excerpt: The sounds of ‘micro-lightning’ have been recorded by NASA’s Perseverance rover, ending a long search for the phenomenon on Mars. ...a microphone on Perseverance ...found 55 such examples, along with signs of electrostatic interference indicative of the phenomenon. They dubbed the electric bursts ‘micro-lightning’, as they are far smaller than the lighting seen on Earth, due to the thin Martian atmosphere....  Full article at https://www.nature.com/articles/d41586-025-03896-7 .

By Javier Barbuzano , Eos/AGU.  Excerpt: In 2020, the...InSight lander...was performing spectacularly, and it had no end in sight. Then, its power began to fade. Fine Martian dust was relentlessly piling on top of its solar panels, blocking sunlight. Mission operators...hoped that occasional wind gusts or passing dust devils would sweep the panels clean... [as] had prolonged the lives of earlier robotic explorers, such as the Spirit and Opportunity rovers. But for  InSight , no such wind ever came, and its batteries slowly ran out of juice. ...Researchers still know little about how winds move across the planet’s surface and interact with dust. To help fill this gap, a group of researchers has now reviewed decades of orbital imagery from two European Space Agency (ESA) spacecraft— Mars Express  and the  ExoMars Trace Gas Orbiter , operational since 2004 and 2016, respectively—looking for dust devils and using them as a proxy for surface winds. ...these orbiters have ...

https://news.berkeley.edu/2023/10/19/webb-telescope-discovers-intense-jet-stream-in-jupiters-atmosphere By Robert Sanders , UC Berkeley News. Excerpt: NASA’s James Webb Space Telescope has discovered a fast-moving jet stream in Jupiter’s atmosphere that is blowing twice as fast as the visible cloud layers below it, creating wind shears that far exceed anything seen on Earth. The high-speed jet stream, which is traveling at 320 miles per hour (515 kilometers per hour) and is more than 3,000 miles (4,800 kilometers) wide, sits over Jupiter’s equator, 15 to 30 miles (25 to 50 kilometers) above the main cloud deck familiar from optical photos. ...winds in the visible cloud layer blow at about 180 mph (250 km/hour). This means that for every kilometer above these visible clouds, the wind speed increases by 7 to 10 kilometers per hour, according to Ricardo Hueso, lead author of a paper describing the findings published today in the journal  Nature Astronomy ....

https://www.kqed.org/forum/2010101893676/aomawa-shields-on-searching-for-life-in-space-and-at-home KQED podcast.  Excerpt: Does it matter if life exists on another planet? To UC Irvine astrobiologist Aomawa Shields it matters in the same way that a mountain matters and screams to be climbed: not knowing is unbearable. Shields has devoted her career to studying the climate and habitability of exoplanets to further the search for extraterrestrial life. She’s also one of very few Black women in a field dominated by white men and a classically trained actor. We talk to her about her journey as a scientist and an artist and her new book “Life on Other Planets: A Memoir of Finding My Place in the Universe.”... See also TED Talk,  How we'll find life on other planets  

https://eos.org/articles/hydrogen-may-push-some-exoplanets-off-a-cliff ] By Julie Nováková , Eos/AGU.  Excerpt: With the discovery of more than 5,000 confirmed exoplanets, astronomers understand more and more about what kinds of planets exist and why. But the data deluge has also thrown into relief the kinds of planets that  don’t  seem to exist. In particular, there is a steep decrease in the abundance of planets larger than approximately 3 Earth radii, a pattern nicknamed the “ radius cliff .” ...new research published in the  Planetary Science Journal  has shown how high-pressure, high-temperature chemical reactions might put a cap on planet growth. ...Missions like NASA’s  Kepler  and  Transiting Exoplanet Survey Satellite  have revealed a curious mystery: Planets 3 times Earth’s size are about 10 times more abundant than planets that are only slightly larger. ...In a first-of-its-kind experiment, researchers placed a thin foil of pr...

https://eos.org/articles/nasas-perseverance-rover-records-the-first-sounds-of-a-dust-devil-on-mars By Jon Kelvey , Eos/AGU.  Excerpt: In a stroke of luck, the SuperCam microphone on Perseverance was turned on the moment a dust devil swept directly over the rover. ...

https://www.science.org/content/article/carbon-dioxide-detected-around-alien-world-first-time By Daniel Clery, Science Magazine.  Excerpt: Astronomers have found carbon dioxide (CO 2 ) in the atmosphere of a Saturn-size planet 700 light-years away—the first unambiguous detection of the gas in a planet beyond the Solar System. The discovery, made by the  James Webb Space Telescope , provides clues to how the planet formed. The result also shows just how quickly Webb may identify a spate of other gases, such as methane and ammonia, which could hint at a planet’s potential habitability for life. ...The Webb telescope is sensitive to infrared wavelengths of light that are mostly blocked by Earth’s atmosphere. ...the infrared sensitivity is also critical for researchers.... When an exoplanet’s orbit takes it in front of its star, some of the starlight passes through the planet’s atmosphere and carries fingerprints of its composition. The atmospheric gases absorb specific wavelength...

https://eos.org/research-spotlights/a-unified-atmospheric-model-for-uranus-and-neptune By  Morgan Rehnberg , Eos/AGU.  Excerpt:  In a new model, three substantial atmospheric layers appear consistent between the ice giants.  The ice giants, Uranus and Neptune, are the least understood planets in the solar system. They remain the only worlds that an orbital spacecraft has not visited. Our limited understanding of them derives largely from the flyby of NASA’s  Voyager 2  probe and subsequent observations with the  Hubble Space Telescope . Yet the ice giants may be most representative of the extrasolar planets in our local vicinity. Why these planets appear so different in color despite having very similar physical properties, including vertical temperature profile and atmospheric composition, is a mystery. Past investigations have attributed Neptune’s deeper blue largely to excess absorption in the red and near infrared from atmospheric methane. ... Irwi...

https://mars.nasa.gov/news/9158/what-sounds-captured-by-nasas-perseverance-rover-reveal-about-mars/ By NASA News.  Excerpt: A new study based on recordings made by the rover finds that the speed of sound is slower on the Red Planet than on Earth and that, mostly, a deep silence prevails. ​ Listen closely to sounds from Mars, recorded by NASA’s Perseverance: the rover’s mechanical whine and click in a light Martian wind; the whir of rotors on Ingenuity, the Mars helicopter; the crackling strike of a rock-zapping laser. An international team of scientists has done just that, performing the first analysis of acoustics on the Red Planet. Their new study reveals how fast sound travels through the extremely thin, mostly carbon dioxide atmosphere, how Mars might sound to human ears, and how scientists can use audio recordings to probe subtle air-pressure changes on another world – and to gauge the health of the rover. ...Most of the sounds in  the study , published April 1 in the jou...

By  Elizabeth Pennisi , Science Magazine.  Excerpt: Today, oxygen fuels much of life on Earth, but it wasn’t always that way. Three billion years ago, this gas was scarce in the atmosphere and oceans. Knowing why oxygen became plentiful could illuminate the evolution of our planet’s flora and fauna, but scientists have struggled to find an explanation satisfying to all. Now a research team has proposed a novel link between how fast our planet spun on its axis, which defines the length of a day, and the ancient production of additional oxygen. Their modeling of Earth’s early days, which incorporates evidence from microbial mats coating the bottom of a shallow, sunlit sinkhole in Lake Huron, produced a surprising conclusion: as Earth’s spin slowed, the resulting longer days could have triggered more photosynthesis from similar mats, allowing oxygen to build up in ancient seas and diffuse up into the atmosphere.  That proposal , described today in Nature Geoscience, has intr...

https://eos.org/research-spotlights/curiosity-rover-reveals-oxygen-mystery-in-martian-atmosphere Source:   By Sarah Stanley, Eos/AGU. Excerpt: The Martian atmosphere is thin and cold and consists mostly of carbon dioxide. Although certainly unsuitable for humans, Martian air could hold clues to whether other life-forms live—or once lived—on the Red Planet. Now Trainer et al. report the first measurements of the five major components of the Martian atmosphere captured over several seasonal cycles. ...On average, the data revealed, the equatorial Martian atmosphere consists of 95% carbon dioxide, 2.59% nitrogen, 1.94% argon, 0.161% oxygen, and 0.058% carbon monoxide. However, throughout the year, some of these concentrations vary widely because of seasonal freezing of carbon dioxide at the planet’s poles, which periodically removes much of this gas from the atmosphere. Seasonal polar freezing—and subsequent thawing—of carbon dioxide also causes atmospheric pressure to rise and fa...

• comparison image between Pioneer’s visit(s) and a more recent ground-based image - http://www.unmannedspaceflight.com/index.php?act=attach&type=post&id=21649 • HST images - http://hubblesite.org/image/3368/news/20-jupiter • animation of GRS shrunk another 20% or so - http://spaceweather.com/archive.php?view=1&day=08&month=06&year=2019 • Christopher Go - http://astro.christone.net/jupiter/ • Anthony Wesley (see 2019 Apr) - http://www.acquerra.com.au/astro/gallery/jupiter/ • Damian Peach (2019) - http://www.damianpeach.com/jupiter.htm

https://eos.org/articles/modeling-the-climates-of-worlds-beyond-earth Source:   By  Katherine Kornei, Eos/AGU. Excerpt: Climate modeling isn’t limited just to planet Earth anymore. In recent decades, researchers have begun modeling the climates of other planets in the solar system and are now simulating conditions on faraway worlds orbiting other stars in the Milky Way galaxy. ...There’s no shortage of planets to study: Nearly 4,000 extrasolar planets (exoplanets) have already been found using such instruments as the Kepler Space Telescope. The team for NASA’s Transiting Exoplanet Survey Satellite (TESS), which was just launched last year, announced the discovery of its third exoplanet at the AAS meeting last week. And an increasing number of worlds are being found that resemble our home planet in size, Shields said. “We are now in the Earth-sized regime.” ...Shields is also studying the climatic effects of ice on exoplanets. Here on Earth, the majority of the sunlight tha...

https://eos.org/articles/how-well-can-the-webb-telescope-detect-signs-of-exoplanet-life Source:    By Lucas Joel, Eos/AGU. Excerpt: ...what NASA’s next-generation, space-based telescope will be able to do: “see the first light of the universe, watch galaxies collide, see stars and planets being born, find and study exoplanets.” ...recent research suggests that the [James Webb Space Telescope (JWST)] might have a tricky time detecting at least one telltale sign of life: oxygen in an exoplanet’s atmosphere. ... Noah Planavsky, a biogeochemist at Yale University, and a team of researchers recently found that a planet’s atmosphere with an extremely small amount of oxygen can still support life. This finding means there could be planets that have only minute oxygen levels—but that nonetheless harbor life—that would appear to be dead to JWST. ...JWST was not originally designed to scan distant planets for their oxygen concentrations. ...JWST’s oxygen-spotting prospects may be di...

http://www.sciencemag.org/news/2018/07/outer-space-may-have-just-gotten-bit-closer Source:   By Paul Voosen, Science Magazine. Excerpt: ...A new study argues that the boundary between Earth’s atmosphere and outer space—known as the Kármán line—is 20 kilometers, or about 20%, closer than scientists thought. Though the new definition won’t make a difference for launching rockets and spacecraft, it could help clarify a legal debate that will set the rules for space policy—and commercial spaceflight—for years to come. Until now, most scientists have said that outer space is 100 kilometers away. At that point, it’s been thought, the speed needed to achieve lift in the superthin atmosphere is equal to the speed needed to simply orbit the planet; once there, a spacecraft’s horizontal pace would counteract the tug of Earth’s gravity. ...A close look shows that the traditional definition flies in the face of evidence, says Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian ...

https://apnews.com/5604f183641342f1ad7f99f2ce665181 Source:   By Emiliano Rodriguez Mega, Associated Press. Excerpt: Astronomers are still finding moons at Jupiter, 400 years after Galileo used his spyglass to spot the first ones. The latest discovery of a dozen small moons brings the total to 79, the most of any planet in our solar system. Scientists were looking for objects on the fringes of the solar system last year when they pointed their telescopes close to Jupiter’s backyard, according to Scott Sheppard of the Carnegie Institute for Science in Washington. They saw a new group of objects moving around the giant gas planet but didn’t know whether they were moons or asteroids passing near Jupiter. ...The team is calling one of the new moons an ‘oddball’ because of its unusual orbit. Sheppard’s girlfriend came up with a name for it: Valetudo, the great-granddaughter of the Roman god Jupiter. Valetudo is in Jupiter’s distant, outer swarm of moons that circles in the opposite ...

Source:  By Shannon Hall, Earth & Space News (EOS; AGU) Excerpt: ...A new hypothesis might reconcile two opposing theories that have tried to explain Mars's mysterious history... suggests that lush periods just long enough to form water-created surface features, such as canyons, punctuated much longer, planet-wide frozen spells. ...In the 1970s, images of Mars taken by the Mariner and Viking spacecraft revealed enormous channels and valley networks—both of which are reminiscent of catastrophic floods and river drainage systems on Earth. The fluvial features were the first sign that 3.8 billion years ago, the planet was once a lush oasis, awash with oceans, lakes, and rivers. ...a 40-year-long debate that has divided planetary astronomers into two camps: those that think Mars must have once contained a thicker and warmer atmosphere—which made the Red Planet hospitable to liquid water and potentially the evolution of life—and those that think Mars was mostly cold save for sho...

Source:   NASA RELEASE 16-076 Excerpt: Using NASA’s Hubble Space Telescope, astronomers have conducted the first search for atmospheres around temperate, Earth-sized planets beyond our solar system and found indications that increase the chances of habitability on two exoplanets. ...the exoplanets TRAPPIST-1b and TRAPPIST-1c, approximately 40 light-years away, are unlikely to have puffy, hydrogen-dominated atmospheres usually found on gaseous worlds. ...The planets orbit a red dwarf star at least 500 million years old, in the constellation of Aquarius. They were discovered in late 2015 through a series of observations by the TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST), a Belgian robotic telescope located at ESA’s (European Space Agency’s) La Silla Observatory in Chile. TRAPPIST-1b completes a circuit around its red dwarf star in 1.5 days and TRAPPIST-1c in 2.4 days. The planets are between 20 and 100 times closer to their star than the Earth is to the sun. B...