If water ever flowed over Mars’ surface, it was a one-night stand, say geochemists studying the properties of an unusual mineral allegedly found by the Opportunity rover at Meridiani Planum.
The possible detection of a normally short-lived mineral called jarosite seems to indicate that there was liquid water on at least Meridiani Planum. But the moisture didn’t last long and hasn’t been back since.

Meteors that would be little more than a flash in the sky on Earth can cause massive explosions, vast dust storms and giant lightning bolts on Mars, say Russian scientists. By adapting some classified Cold War equations created to predict what nuclear blasts would do in Earth’s atmosphere, scientists from the Russian Academy of Sciences Institute for Dynamics of Geospheres think they have a way of predicting how meteors would behave when they bust through the thin martian atmosphere.