Unless you’re Matt Damon, you’re unlikely to think about agriculture on Mars anytime soon, but it’s still interesting to speculate on what the weather might have been like there in the past. EarthSky posted a story this week about how geologists and other scientists are determining the past weather on Mars and the signs for evidence of liquid water that you can see on the surface.  You can read the story here.

Valley networks on Mars show evidence for surface runoff driven by rainfall. Image via Elsevier.