Astro Blog

By Daniel Clery , Science.  Excerpt: Astronomers studying the murky center of our Milky Way Galaxy have discovered something they never expected:  a pair of young stars orbiting each other near the supermassive black hole that is our Galaxy’s dark heart . The observation—reported today in Nature Communications—comes as a surprise because astrophysicists had thought the black hole’s intense gravity would either rip the stars in such a pair apart or squash them together. But the new object, dubbed D9, shows that such a “binary” can survive, at least briefly, near the black hole, and it could help explain other mysterious objects in the vicinity. ...For many years, two teams, in California and Germany, monitored the  closest of those stars . About 20 years ago, both proved the star’s eccentric, high-speed orbit could only arise if it was circling a compact object with extreme mass—a black hole. For that work, the teams’ leaders, Reinhard Genzel of the Max Planck Institu...

By Valeriy Vasilyev et al, Science.  Editor's Summary: Solar flares are bright, transient, multiwavelength emissions from active regions on the Sun. The most intense directly observed solar flares release energies of about 10 32  erg. It is unclear whether the Sun can produce more intense flares than that or how often they might occur. Vasilyev  et al . investigated brightness measurements of 56,000 Sun-like stars observed by the Kepler space telescope. They identified almost 3000 bright stellar flares with energies of about 10 34  to 10 35  erg, which are called superflares. The occurrence rate is about one superflare per star per century. If the Sun behaves like the stars in this sample, then it could produce superflares at a similar rate. —Keith T. Smith.  Full article at https://www.science.org/doi/10.1126/science.adl5441 . 

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...