Patterns In Mars Craters Give Picture Of Drying Lakes

Networks of giant polygonal troughs etched across crater basins on Mars have been identified as desiccation cracks caused by evaporating lakes, providing further evidence of a warmer, wetter Martian past. The findings were presented at the European Planetary Science Congress by PhD student Mr. M. Ramy El Maarry of the Max Planck Institute for Solar System Research.

http://www.marsdaily.com/reports/Patterns_In_Mars_Craters_Give_Picture_Of_Drying_Lakes_999.html