Astro Blog

By ScienceAdvisor.  Excerpt: Victory is sweet for astronomers, who have just discovered the presence of a sugar molecule in interstellar space —a discovery that may have implications for the origin of life. The molecule, erythrulose, is also found on Earth in raspberries and self-tanner. ...researchers observed a large cloud of gas and dust called G+0.693–0.027, located about 27,000 light-years from Earth, using ...radio waves, which can pass through gas and dust and reveal information about the molecules within. ...Erythrulose isn’t the first sugar to be detected outside Earth, as samples from meteorites and the asteroid Bennu have shown ribose and glucose. But the new, more complex sugar is the first to be detected in interstellar space—and a further sign of how the carbon-rich building blocks of genetic material could have first formed in space. “ We have been waiting for an actual detection like this ,” geochemist Yoshihiro Furukawa, who was not involved in the study, told The ...

By Elise Cutts , Science.  Excerpt: Astronomers are planning ambitious telescopes to search for signs of life on distant planets. A newly discovered world, announced here last week at the Rocky Worlds conference and  published yesterday  in  The Astrophysical Journal Letters , might just be the perfect target. The planet, called HD 137010 b, is almost exactly Earth-size. At 355 days, its orbit is almost exactly Earth-like, too. And its star is bright and just 146 light-years away–close enough to be observed in detail with future telescopes....  Full article at https://www.science.org/content/article/earth-size-planet-spotted-yearlong-orbit . 

By Science Advisor.  Excerpt: If the space community had to place bets on the most promising candidate for life in the solar system, Enceladus would probably win...a salty liquid ocean, as well as compounds like phosphorus and complex hydrocarbons, all necessary for life as we know it on Earth. But the world had been missing one crucial factor: stability. Since life takes a long time to evolve, a good candidate world should remain stable over many millions or billions of years. Stability is often determined through a world’s heat balance, where the amount of energy it receives from its star equals the amount of energy it radiates outward. Though scientists knew that Enceladus’s southern pole leaked out heat from the forces of Saturn’s gravity stretching and squashing the world, its heat balance was still off. But when researchers used data from NASA’s Cassini mission to study Enceladus’s north pole, they found that  the surface was around 7ºC warmer than the models predicted ....

By David L. Chandler , Sky & Telescope.  Excerpt: The Perseverance has found compounds associated with life on Earth. But whether they indicate life on Mars awaits sample return. ...One rock,...is dotted with colored spots, ...The leopard spots, it turns out, appear to be  reaction fronts  — areas of contact between an expanding chemical reaction and surrounding rock. The material in the rings is composed of two different iron-rich minerals: vivianite (iron phosphate) and greigite (iron sulfide). Both of these minerals, on Earth, are usually associated with decaying plant matter or are products of microbial activity. ...The team cautions, however, that a non-biological formation process has not been ruled out.  Full article at https://skyandtelescope.org/astronomy-news/best-evidence-yet-for-past-life-on-mars/ .  See also New York Times article .

By Paul Voosen , Science.  Excerpt: NASA’s Curiosity rover has detected what could be a chemical relic of long-ago life on Mars: long-chain organic molecules. Found after painstaking reanalysis of data on a sample drilled from a lake that dried up billions of years ago, the molecules likely derived from fatty acids, a common building block of cell membranes on Earth. The finding,  published  today in the Proceedings of the National Academy of Sciences, is not a definite detection of past life; the fatty acids could also have formed without life. But it’s another in a series of tantalizing hints....  Full article at https://www.science.org/content/article/curiosity-rover-detects-long-chain-carbon-molecules-mars . 

By Robert Sanders , UC Berkeley News.  Excerpt: Mars today is a cold, dry, dusty planet with its only obvious water locked up in frozen polar ice caps. But billions of years ago, it appears to have had sandy beaches lapped by waves along the shoreline of a vast ocean. The evidence for beaches on Mars comes from a Chinese rover, called Zhurong, that landed on the planet in 2021. During its short life it detected evidence of underground beach deposits in an area thought to have once been the site of an ancient sea, bolstering the idea that the planet long ago had large bodies of water. ...between May 2021 and May 2022, Zhurong traveled 1.9 kilometers (1.2 miles) roughly perpendicular to escarpments thought to be an ancient shoreline from a time — 4 billion years ago — when Mars had a thicker atmosphere and a warmer climate. Along its path, the rover used ground penetrating radar (GPR) to probe up to 80 meters (260 feet) beneath the surface. ...“The structures don’t look like sand du...

By Daniel P. Glavin et al, Nature Astronomy.  Abstract Excerpt: Organic matter in meteorites reveals clues about early Solar System chemistry and the origin of molecules important to life.... Samples returned from the B-type asteroid Bennu by the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer mission ...show that Bennu samples are volatile rich, with more carbon, nitrogen and ammonia than samples from asteroid Ryugu and most meteorites. ...Bennu’s parent asteroid developed in or accreted ices from a reservoir in the outer Solar System where ammonia ice was stable. ...The transport and delivery of organic compounds from these bodies could have been a source of molecules available for the emergence of life on Earth and potentially elsewhere....  Full article at https://www.nature.com/articles/s41550-024-02472-9 .  See also Nature article An evaporite sequence from ancient brine recorded in Bennu samples [Brines ...are environment...

By Robin George Andrews , Science.  Excerpt: ...Jupiter’s moon Europa ...NASA hopes will greet its Europa Clipper spacecraft, which will begin its journey to the Jupiter system next month. ...Something extraordinary is concealed beneath the ice: a liquid saltwater ocean, potentially as clement and welcoming to life as Earth’s. ...Equipped with a battery of nine science instruments, Clipper will swoop past Europa in a series of nearly 50 ice-skimming flybys, remotely probing the ocean in hopes of finding a chemistry that could support life. ...“We’re not a life search mission. We’re a habitability mission,” says Robert Pappalardo, Clipper’s project scientist at the Jet Propulsion Laboratory (JPL), which manages the mission. But even Pappalardo, a cautious scientist who is constitutionally averse to hyperbole, says finding a hint of life is “not out of the question.”...  Full article at https://www.science.org/content/article/nasa-spacecraft-probe-possibility-life-europa-s-salty...

By Hannah Richter , Science.  Excerpt: One of the classic tropes of science fiction is  terraforming Mars : warming up our cold neighbor so it could support human civilization. The idea might not be so far-fetched,  research published today  in Science Advances suggests. Injecting tiny particles into Mars’s atmosphere could warm the planet by more than 10°C in a matter of months, researchers find—enough to sustain liquid water. Although the scheme would require about 2 million tons of particles per year, they could be manufactured from readily available ingredients found in martian dust....  Full article at https://www.science.org/content/article/terraforming-mars-could-be-easier-scientists-thought . 

By DANIEL CLERY , Science.  Excerpt: Living on one of the seven Earth-size planets in the TRAPPIST-1 system would be strange.... Looming ominously in the sky is an enormous red star, prone to fiery outbursts and appearing several times bigger than the Sun. Hours of the day don’t exist; each planet is tidally locked to the star so that one side is forever scorchingly hot, the other eternally frozen. Along the margin dividing the day- and nightsides—the only place with a tolerable climate—a ceaseless wind blows and the star hangs on the horizon, in perpetual sunset. A short stroll into the dark side brings your planetary companions into view. Every few days one or more passes overhead like a floating lantern, larger than the Moon. ...the quest to learn whether one of the TRAPPIST-1 planets could make a comfortable home for our imaginary observer has been an exercise in frustration. When the  seven known planets around TRAPPIST-1 were revealed in 2017 , they were ...the best plac...

By ARIELLE FROMMER , Sky & Telescope.  Excerpt: In the search for planets around other stars, astronomers often seek worlds that are most like our own. The discovery of Gliese 12b — the closest, transiting, temperate, Earth-size planet found to date — promises possibilities for understanding how terrestrial planets become habitable. Gliese 12b orbits a cool red dwarf star around 40 light-years away — practically neighborly compared to other exoplanets — with a period of 12.8 days. Its distance from its host star means that its surface might be temperate enough for life, with a temperature of 107°F (42°C). ...Gliese 12b was initially detected by NASA’s Transiting Exoplanet Survey Satellite (TESS), a mission that searches for changes in stellar brightness and records  transits  that occur when a planet passes in front of its host star. ...Red dwarf stars, or  M  stars, have small masses and radii and low luminosities, which means any planets orbiting in t...

https://eos.org/research-spotlights/scientists-investigate-how-heat-rises-through-europas-ocean By Rebecca Owen , Eos/AGU.  Excerpt: Europa, one of Jupiter’s many moons, may be capable of supporting life because its icy surface likely obscures a deep, salty ocean.  Europa’s ocean  is also in direct contact with its mantle rocks, and interactions between rock, water, and ice could provide energy to sustain life. Lemasquerier et al.  examined the way heating from Europa’s mantle could drive ocean circulation under the icy crust. The researchers modeled Europa’s ocean to further understand how heating patterns from deep inside the moon may affect the thickness of its icy surface. ...Mantle heat ...comes in two forms. Radiogenic heating is caused by the decay of radioactive materials in the mantle, and  tidal heating  is caused by the deformation Europa undergoes as it orbits Jupiter and experiences its strong gravitational pull. Tidal heating is uneven; it’s h...

https://www.nytimes.com/2023/12/14/science/enceladus-moon-cyanide-life-saturn.html By Kenneth Chang , The New York Times.  Excerpt: Scientists have detected a poison among the spray of molecules emanating from a small moon of Saturn. That adds to existing intrigue about the possibility of life there. The poison is hydrogen cyanide, a colorless gas that is deadly to many Earth creatures. But it could have played a key role in chemical reactions that created the ingredients that set the stage for the advent of life. ...Mr. Peter and his collaborators, Tom Nordheim and Kevin Hand of NASA’s Jet Propulsion Laboratory in California, reported their findings in a paper published on Thursday in the journal Nature Astronomy.... 

https://www.science.org/doi/10.1126/science.adg4155 By SAMANTHA K. TRUMBO  AND  MICHAEL E. BROWN , Science.  Excerpt: [Editor's summary:] Europa, an icy moon of Jupiter, has a subsurface ocean beneath a crust of water ice. Solid carbon dioxide (CO 2 ) has previously been observed on its surface, but the source was unknown. Two teams analyzed infrared spectroscopy of Europa from the James Webb Space Telescope to investigate the CO 2  source. Trumbo and Brown found that the CO 2  is concentrated in a region with geology that indicates transport of material to the surface from within the moon, and they discuss the implications for the composition of Europa’s internal ocean. Villanueva  et al . also identified an internal origin of the CO 2  and measured its  12 C/ 13 C isotope ratio. They searched for plumes of volatile material breaching the surface but found a lower activity than earlier observations. Together, these studies demonstrate t...

https://eos.org/articles/subsurface-oceans-could-boost-exoplanet-habitability By  Javier Barbuzano , Eos/AGU.  Excerpt: A group of researchers led by planetary scientist  Lujendra Ojha  of Rutgers University crunched the numbers to reveal that our galaxy is likely brimming with planets hosting subsurface oceans like those on  Enceladus ,  Europa , and  Ganymede . “Before we started to consider this subsurface water, it was estimated that around one rocky planet [orbiting] every 100 stars would have liquid water,” Ojha said. “The new model shows that if the conditions are right, this could approach one planet per star.”... 

https://www.science.org/content/article/ancient-mud-cracks-mars-point-conditions-favorable-life By Phil Jacobs, Science.  Excerpt: ...the discovery of distinctive mud cracks on the planet’s surface suggest ancient Mars cycled through sustained wet and dry seasons for millions of years. Not only would the climate have been habitable, scientists say, but the cycling might have also given the basic chemistry of life a boost. The discovery, reported today in Nature, is  compelling evidence for an Earth-like climate on early Mars .... the Curiosity rover has discovered patterns of hexagon-shaped cracks in ancient rocks that add to the evidence for a sustained warm climate. They resemble patterns found on Earth in places like Death Valley, where they only form after years of wet-dry cycling.... 

https://www.nasa.gov/feature/goddard/2023/webb-detects-water-vapor-in-rocky-planet-forming-zone By NASA.  Excerpt: Water is essential for life as we know it. However, scientists debate how it reached the Earth and whether the same processes could seed rocky exoplanets orbiting distant stars. New insights may come from the planetary system PDS 70, located 370 light-years away. The star hosts both an inner disk and outer disk of gas and dust, separated by a 5 billion-mile-wide (8 billion kilometer) gap, and within that gap are two known gas-giant planets. New measurements by NASA’s James Webb Space Telescope’s MIRI (Mid-Infrared Instrument) have detected water vapor in the system’s inner disk, at distances of less than 100 million miles (160 million kilometers) from the star – the region where rocky, terrestrial planets may be forming. (The Earth orbits 93 million miles from our Sun.) This is the first detection of water in the terrestrial region of a disk already known to host two o...

https://skyandtelescope.org/astronomy-news/perseverance-finds-complex-organics-not-life-on-mars/ By Colin Stuart, Sky & Telescope Magazine.  Excerpt: Planetary scientists analyzing data from NASA’s Perseverance rover have found signs of organic molecules on Mars, hinting that the planet had a more complex geochemical cycle in the past than previously thought. If true, it shows that the building blocks of life have been present on the Red Planet for around billions of years. These new findings, published in  Nature , come from examining the floor of Jezero Crater, a 45-kilometer- (28-mile-) wide impact basin just north of the Martian equator. NASA picked it as Perseverance’s landing site due to geological signs that an ancient river flooded into the crater some 2.5 billion years ago.... 

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://www.fraknoi.com/astronomy/pahs-found-in-distant-galaxy/ By Andrew Fraknoi.  Excerpt: Astronomers working with the Webb Space Telescope have found a fortunate alignment in the sky that has enabled them to detect the faint signal of a complex building block of life just 1.5 billion years after the origin of the universe. The discovery of PAH’s (polycyclic aromatic hydrocarbons) so soon after the Big Bang is another powerful demonstration that assembling the ingredients for the chemistry of life is a process that began in the vast clouds of raw material between the stars. And, it seems, it began quite quickly after the first generations of stars produced the required elements....