Astro Blog

https://www.science.org/content/article/nasa-lays-out-vision-robotic-mars-exploration By Paul Voosen, Science.  Excerpt: Rover by rover, NASA’s exploration of Mars is building to an expensive climax: a multibillion-dollar mission later this decade to collect the rock samples  currently being gathered by the Perseverance rover  and return them to Earth. But then what? NASA ...envisions a series of lower cost Mars missions, costing up to $300 million, at every 2-year launch window. The program could begin as soon as 2030, said Eric Ianson, director of NASA’s Mars Exploration Program, in a  presentation today  to the U.S. National Academies of Sciences, Engineering, and Medicine. ...planetary scientists have been investigating what cheaper missions to Mars might look like. In 2018, Mars Cube One, a pair of small spacecraft, flew along with the InSight lander, successfully relaying its signal to Earth as they flew past the planet. And the Ingenuity helicopter on Mars, which landed with Per

https://www.science.org/content/article/earth-higher-risk-big-asteroid-strike-satellite-data-suggest By Paul Voosen, Science.  Excerpt: At a basic level, humanity’s survival odds come down to one thing: the chances of a giant space rock slamming into the planet and sending us the way of the dinosaurs. One way to calibrate that hazard is to look at the size of Earth’s recent large impact craters. And a provocative new study suggests they are bigger than previously thought—meaning Earth is more at risk of getting hit hard, says James Garvin, chief scientist of NASA’s Goddard Space Flight Center,  who presented the work  last week at the Lunar and Planetary Science Conference. ...Using a new catalog of high-resolution satellite imagery, Garvin and his colleagues identified large rings around three impact craters and one probable one that are 1 million years old or younger. To Garvin, the rings imply the craters are tens of kilometers wider, and record far more violent events, than researc

https://www.science.org/content/article/active-volcano-shows-venus-living-planet By Paul Voosen, Science.  Excerpt: Choked by a smog of sulfuric acid and scorched by temperatures hot enough to melt lead, the surface of Venus is sure to be lifeless. For decades, researchers also thought the planet itself was dead, capped by a thick, stagnant lid of crust and unaltered by active rifts or volcanoes. But hints of volcanism have mounted recently, and now comes the best one yet: direct evidence for an eruption. Geologically, at least, Venus is alive. The discovery comes from NASA’s Magellan spacecraft, which orbited Venus some 30 years ago and used radar to peer through the thick clouds. Images made 8 months apart show a volcano’s circular mouth, or caldera, growing dramatically in a sudden collapse. On Earth, such collapses occur when magma that had supported the caldera vents or drains away, as happened during a 2018 eruption at Hawaii’s Kilauea volcano. ...The discovery, published today i