Astro Blog

By ScienceAdviser.  Excerpt: Understanding how planets form in the disks of dust and gas around newborn planets is a work in progress. Only recently have astronomers  spied planets carving out rings in the disks  by scooping up material. But some disks have a spiral structure. Is that the result of gravitational interactions in the disk itself, before planets form, or are newborn planets themselves warping the disk into a spiral? A team of astronomers say they’ve resolved this chicken-and-egg puzzle using the Atacama Large Millimeter/submillimeter Array (ALMA), a collection of 66 dish antennas high up in the Chilean Andes which can see dust in disks but not the planets themselves. If the spiral arms formed in the disk spontaneously, over time they would wind tighter, like the spring in a wind-up clock. Arms formed by planets would keep their shape as they move around the nascent star. The team used archival and new images taken over 7 years of the young star IM Lup to mak...

By David L. Chandler , Sky & Telescope.  Excerpt: The Perseverance has found compounds associated with life on Earth. But whether they indicate life on Mars awaits sample return. ...One rock,...is dotted with colored spots, ...The leopard spots, it turns out, appear to be  reaction fronts  — areas of contact between an expanding chemical reaction and surrounding rock. The material in the rings is composed of two different iron-rich minerals: vivianite (iron phosphate) and greigite (iron sulfide). Both of these minerals, on Earth, are usually associated with decaying plant matter or are products of microbial activity. ...The team cautions, however, that a non-biological formation process has not been ruled out.  Full article at https://skyandtelescope.org/astronomy-news/best-evidence-yet-for-past-life-on-mars/ .  See also New York Times article .

By Kimberly M. S. Cartier , Eos/AGU.  Excerpt: On 1 July 2025, astronomers detected a visitor from the deep reaches of space. At the time of discovery, the object was just inside Jupiter’s orbit and was zipping across our solar system 4 times faster than the New Horizons probe sped past Pluto. It was first spotted by the Asteroid Terrestrial-impact Last Alert System ( ATLAS ) in Chile, which was specifically designed to spot small, fast-moving objects like this. ATLAS sent out a public,  automated alert , and when astronomers saw it, they quickly went to work calculating the object’s orbit and trajectory....  Full article at https://eos.org/features/how-an-interstellar-interloper-spurred-astronomers-into-action .