The decades old idea that our solar system’s Oort Cloud is continually perturbed by a heretofore undetected low mass Red Dwarf star remains the best explanation for periodicities found in Earth’s impact record. Or so says a well known physicist who has long championed this idea.
Ultra-Diffuse Galaxies are strange because they're as large as the Milky Way, but have far fewer stars. It's as if they're puffed up for some reason. Determining what's going on with them could help confirm the Lambda-CDM model. A new proposed instrument for the Extremely Large Telescope could give astronomers their best look yet at these strange galaxies.
NASA's ESCAPADE mission features a pair of identical spacecraft on their way to Mars. They launched outside of the normal launch window, so they'll perform powered slingshot maneuvers to boost their speed. Once there, they'll "fly" in formation and study how the solar wind interacts with what remains of Mars ancient magnetosphere.
We typically think of the Moon as a static, floating object that has remained the same for basically its entire lifetime, with an occasional asteroid impact serving as an exception. That understanding is grounded in physics - the Moon should have cooled rapidly after forming when a huge protoplanet hit the early Earth around 4.5 billion years ago. But, some lunar material returned from the Chang’e-5 mission was notably formed only around two billion years ago, yet appeared to be volcanic in origin. So how did a world that was supposed to have settled down without volcanism remain hot enough to create these materials more than two billion years after its violent birth? A new paper from Miao Chen of the Chengdu University of Technology and his colleagues, and recently published in the journal Planet, offers an explanation - tidal heating.
Flashback to 1977. Jimmy Carter was U.S. president, Star Wars was a box office hit, and the two Voyager spacecraft departed on an historic Grand Tour of the solar system. Now, teams at NASA’s Jet Propulsion Laboratory are working to keep the missions active, as they push the boundaries of interstellar space beyond the solar system.
In a pinch, we could use a stand-off nuclear blast to redirect a dangerous asteroid on short notice. There's no atmospheric shock wave in space, but the x-ray pulse could still deflect the space rock. But asteroids aren't round and uniform, so their weird shapes make it difficult.
Targets of opportunity sometimes happen in astronomy, and we got a major one when the third interstellar object, 3I/ATLAS, was discovered in July 2025. And it just so happens that in the intervening years between the last known interstellar visitor (2I/Borisov in 2019), we got a major upgrade in our observational capabilities with the launch of the James Webb Space Telescope (JWST). A new paper from a team of researchers led by Dr. Silvia Protopapa of NASA’s Goddard Space Flight Center and the Southwest Research Institute, and published in The Astrophysical Journal Letters, details JWST’s findings on the water ice content of this most recent visitor from beyond our solar system.
