Martian valley networks
Martian valleys could have been carved by surprisingly little water
Vast valley networks on Mars have suggested that water may have flowed there for millions of years. Now a study at Brown University suggests the valleys could have been carved by much less water in as little as a few hundred to 10,000 years. The findings are consistent with the idea that early Mars may have been cold and icy, with surface water flowing sporadically in response to short-term climate changes.