What's Carving Active Gullies on Mars? It's Not Water

Scientists were shocked when they received the first images of Martian gullies. They were even more shocked as those gullies appeared to change over time. Their similarities to gullies seen on Earth were uncanny, but all of Earth’s gullies are formed by the water run-off, and Martian is too cold and has too sparse an atmosphere to have liquid water on its surface. Whatever has been causing those changing gullies couldn’t have been water, so what was it? A new paper from Apolline Leclef of the Institut d’Astrophysique Spatiale at Université Paris-Saclay and her colleagues, available in pre-print on arXiv, shows how they are likely caused by CO2 frost turning into a fluid.

NASA's Next Great Observatory Could Spot Oceans on Distant Worlds

We’ve found over 5,500 exoplanets so far. Dozens of them have been in the habitable zone of their parent stars, where, at least in theory, they could host an ocean. But we’ve never definitively found a liquid ocean on another planet. A new paper from researchers Eleanor Cornish and Tyler Robinson of the University of Arizona, available in pre-print on arXiv and submitted to the Astrophysical Journal, looks at a unique way we might be able to find one - by looking for its “glint”.

eROSITA's Second Data Release Catalog Delivering the Most Comprehensive High-Energy Census of the Cosmos to Date

The eROSITA Consortium has issued the survey's second data release (DR2), nearly doubling the previously known eROSITA X-ray sources to two million.

Unexplained Gamma-Rays from the Galactic Center Could be from Self-Annihilating Dark Matter

Over a decade ago, the Fermi satellite detected an excess of gamma-ray emissions in the galactic center. Potential explanations included Sgr. A*, the Milky Way's SMBH, pulsars, and even self-annihilating dark matter. There's no clear answer yet, since the region is so difficult to observe. But recent research shows that dark matter can't be ruled out.

Ancient Swedish Goths Had Surprisingly Accurate Calendars

Ancient Swedish pagans had surprisingly accurate calendars and the ability to measure phases of the Moon to an incredible precision.

New Revelations About the Origin of Interstellar Comet 3I/ATLAS

UK astronomers have uncovered new clues about the origin of 3I/Atlas – only the third known object from beyond our Solar System ever spotted in our cosmic neighbourhood.

New Research Says that Early Galaxies Could be Sending us Neutrinos

Those "Little Red Dots" discovered by the James Webb Space Telescope, galaxies that existed during the very early Universe, could be sending neutrino particles that are reaching us today.