The idea is based on new findings that the moon, where no liquid water has been found, contains gullies similar to those found on Mars. Gwendolyn Bart, a graduate student in planetary sciences at ...

Planetary geologists and astronomers studying Mars have known for decades that water was once likely present on the planet, after NASA's Mariner 9 mission captured images of dry gullies in the 1970s.

Roundheaded gullies slice into that same smooth layer, while strange tongues of who-knows-what lap at the slopes beneath them. Landscapes like this are changing the way geologists look at Mars.

Studying gullies is one way to avoid a research rut. Rodriguez, J.A.P. VC Gulick, RL Santiago, MZ Hernández, AG Fairen, VR Baker, T Platz, JS Kargel, Y Jianguo, N Glines 2015. Flooding in Highly ...

Some of the meandering valley networks that lace the landscape may indicate that Mars was a warmer, wetter world billions of years ago. But other features, including gullies found around many impact ...