Mars

There’s a hole in the Martian atmosphere that opens once every two years, venting the planet’s limited water supply into space — and dumping the rest of the water at the planet’s poles. That’s the explanation advanced by a team of Russian and German scientists who studied the odd behavior of water on the Red Planet. Earthbound scientists can see that there’s water vapor high in the Martian atmosphere, and that water is migrating to the planet’s poles. But until now, there was no good explanation for how the Martian water cycle works, or why the once-drenched planet is now … Read more

Mars was wet, until suddenly it wasn’t. Scientists have long seen dry riverbeds slashed across the surface of Mars as evidence that water once flowed freely on the planet. And in 2012, NASA’s Curiosity space rover sent back images of smooth, round pebbles from the bottom of one such riverbed, their lack of rough edges evidence that water had once flowed over them. Now, a new study published today (March 27) in the journal Science Advances catalogs those rivers and reports that their waters likely flowed heavily well into the last epoch, before Mars entirely dried up. “It’s already hard … Read more