Astro Blog

By Jonathan O’Callaghan , The New York Times.  Excerpt: We might finally understand what’s going on inside Uranus and Neptune, and the answer is pretty surprising: They may each contain an ocean of water. ...The idea about the two ice giant planets — so-called because of the freezing conditions in which they formed — was put forward by Burkhard Militzer, a planetary scientist from the University of California, Berkeley, and was  published Monday in the Proceedings of the National Academy of Sciences . It could explain the strange magnetic fields of both worlds, which are unlike any other in the solar system....  Full article at https://www.nytimes.com/2024/11/25/science/uranus-neptune-oceans.html .  See also UC Berkeley News A clue to what lies beneath the bland surfaces of Uranus and Neptune , By Robert Sanders. 

By Katherine Kornei , Eos/AGU.  Excerpt: In 2011, a striking black rock about the size of an apple was discovered in the Sahara desert. ...that meteorite, which has come to be known as NWA 7034, or “Black Beauty,” is different from most other meteorites: It’s a chunk of Mars. ...Tiny grains of zircon from NWA 7034 have now revealed that hydrothermal activity likely persisted in Mars’s crust 4.45 billion years ago. That’s the earliest indirect evidence of water on the Red Planet....  Full article at https://eos.org/articles/martian-meteorite-points-to-ancient-hydrothermal-activity . 

By Zexian Cui et al, Science.  Summary: Between 1969 and 1976, the Apollo and Luna missions collected samples from the ...near side of the Moon—the one that always faces Earth. Observations from lunar orbit have shown that the far side has very different geology from the near side, for unknown reasons. ...In June 2024, the Chang’e-6 spacecraft landed within an impact basin on the far side of the Moon, collected samples, then brought them back to Earth. In a new Science paper , researchers present early results from analyses of a Chang’e-6 sample, which contains volcanic basalt...the volcanic eruption occurred 2.8 billion years ago....  Paper at https://www.science.org/doi/10.1126/science.adt1093 . 

By  Jamie M. Jasinsk  et al, Nature Astronomy. Summary: A human spacecraft has only gotten close to Uranus once—in 1986, when Voyager 2 drifted past the distant planet. That flyby indicated that   Uranus was weird in several ways , which astronomers have spent decades trying to explain. Now, a new analysis in   Nature Astronomy   suggests the probe   just happened to arrive there on an off day . Voyager 2’s data indicated that Uranus had an “unusually oblique and off-centered magnetic field” with inexplicably intense electron radiation belts and a severely plasma-depleted magnetosphere,” the team behind the new work writes. But by mining old data from the mission, the scientists found evidence for a super strong solar wind that likely squished the magnetosphere just prior to the probe’s readings. This would have pushed any plasma too close to the planet to detect, and filled the radiation belts with high-energy particles. https://www.nature.com/articles/s41...

By Saima May Sidik , Eos/AGU.  Excerpt: Geological evidence on Mars indicates that 3.6 billion years ago, an intense pulse of water carved rivers and lakes across the planet, an abrupt shift from the preceding 500-million-year era of much gentler fluvial activity. Researchers have long  puzzled over  the cause. A new study by  Buhler  shows, paradoxically, that the collapse of the Martian atmosphere and entry into a  colder  climate may have melted the polar ice cap and triggered global-scale flooding. ...In total, about 4% to 40% of the water ice could have melted, an amount of water equivalent to between 20% and 200% of the  water currently found near the surface on Mars ....  Full article at https://eos.org/research-spotlights/how-an-ocean-sized-lake-may-have-formed-on-ancient-mars . 

By Damond Benningfield , Eos/AGU.  Excerpt: Earth’s future is bleak. At best, our planet will become a burned-out cinder as the Sun expands at the end of its life. At worst, it will be engulfed by the Sun, leaving no trace that it ever existed. Astronomers have found a clue as to which path Earth might follow in a star system about 4,300 light-years away. There, a rocky planet orbits the remains of a once Sun-like star at a distance similar to where Earth could park if it survives our own star’s death throes. The system “may offer a glimpse into the possible survival of planet Earth in the distant future,” according to  a new study  published in  Nature Astronomy . The system,  KMT-2020-BLG-0414L , was discovered in 2020 by the  Korea Microlensing Telescope Network , a set of three automated 1.6-meter telescopes in the Southern Hemisphere....  Full article at https://eos.org/articles/earth-may-survive-the-suns-demise .