Posts

The top candidate for life beyond Earth just got even better

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 ....

Webb Telescope Spies Io’s Volcanic Activity and Sulfurous Atmosphere

By Sarah Stanley , Eos/AGU.  Excerpt: Trapped in a gravitational push and pull between Jupiter and other Jovian moons, Io is constantly being  stretched and compressed . Heat generated by these contortions has melted  pockets  of the moon’s interior so much that Io is our solar system’s most volcanically active body. The  James Webb Space Telescope (JWST)  recently opened up new opportunities to get to know Io. Using data from its Near Infrared Spectrograph—which sees wavelengths corresponding to  different compositions and temperatures — de Pater et al.  have made new discoveries about Io’s volcanoes and atmosphere. The researchers first looked at Io  in November 2022  and found an extremely energetic volcanic eruption in the vicinity of the lava flow field Kanehekili Fluctus. These observations revealed, for the first time, that some volcanoes on Io emit an excited form of sulfur monoxide gas, confirming the team’s 2-decade-old hypoth...

Startup pioneers subscription service for space-based astronomy

By Daniel Clery , Science.  Excerpt: Later this month, a diminutive telescope called Mauve will take to space. Unusually, a government space agency is not the owner. Rather, Mauve was built by a startup company that will sell astronomical data to researchers by subscription. With a 13-centimeter telescope squeezed into a satellite smaller than a microwave oven, Mauve is squarely in the little league of astronomical missions. But its creators hope it will set a precedent....  Full article at https://www.science.org/content/article/startup-pioneers-subscription-service-space-based-astronomy .

Martian Dust Devils Reveal Dynamic Surface Winds

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 ...

Zircon Crystals Could Reveal Earth’s Path Among the Stars

By Tom Metcalfe , Eos/AGU.  Excerpt: Tiny crystals in Earth’s crust may have recorded meteorite and comet impacts as our planet traveled through the spiral arms of the Milky Way over more than 4 billion years, according to new research. ...The key to the latest research was in the ratios of isotopes—forms of the same chemical element that have different numbers of neutrons—in the oxygen atoms of zircon’s silicate group. The relative levels of oxygen isotopes in samples of zircon crystals can tell geologists whether the crystals formed high in the crust, perhaps while interacting with water and sediments, or deeper within Earth’s mantle. ...The scientists evaluated the data’s “ kurtosis ,” or the measure of how flat or peaked a distribution is. ...The researchers determined that periods of high oxygen isotope kurtosis corresponded to times when our solar system was crossing the dense spiral arms of the Milky Way galaxy. Such crossings occurred roughly every 187 million years on aver...

Scientists May Have Finally Detected a Solid Inner Core on Mars

By Javier Barbuzano , Eos/AGU.  Excerpt: Almost a decade after NASA’s InSight mission put the first working seismometer on the Martian surface, ...scientists reported seismic evidence that Mars has a solid inner core, an unexpected finding that challenges earlier studies that suggested the planet’s core was entirely molten. ...the interior of Mars has layers... [with] different densities and can be solid or liquid. As seismic waves move through the layers, they are bent or reflected, especially at boundaries where density changes sharply. ...Previous analyses of InSight data had already mapped the structure of the Martian  crust  and  mantle  and also revealed that the planet has a surprisingly  large molten metallic core , spanning nearly half its radius. ...the new finding caught InSight scientists off guard....  Full article at https://eos.org/articles/scientists-may-have-finally-detected-a-solid-inner-core-on-mars .  See also Dust devil migrat...

Exoplanet without a sun found gobbling up 6 billion tons of gas and dust per second

By Victoria Corless , Space.com.  Excerpt: Scientists have identified a lone planet with a ferocious appetite. Located in the Chamaeleon constellation roughly 620 light-years away, the rogue planet, named Cha 1107-7626, exists in the vast emptiness of space, far from the warmth of any star. ...Using the  European Southern Observatory 's (ESO)  Very Large Telescope  (VLT), astronomers have caught it pulling in gas and dust at an astonishing rate: six billion tons every single second. Never before has a rogue planet, or any planet, been observed growing this fast. "This is the strongest accretion episode ever recorded for a planetary-mass object," Almendros-Abad said. With a mass equivalent to between five and 10 Jupiters, Cha 1107-7626 is one of the lowest-mass free-floating planets known to host a disk and show active accretion. Observations from ESO's VLT and NASA's  James Webb Space Telescope  (JWST) reveal telltale signs of a rich, evolving system ...sil...