There is no longer any question: water is present on Mars -- albeit only in the form of ice or vapour. Today, the questions that remain concern liquid water: was the planet's H2O ever in a liquid state and, if so, did it flow on the surface, or was it confined to subterranean locations?
New evidence found by Curiosity in the Gale Crater suggests that not only did liquid water flow on the planet's surface, it did so for long enough to build up Mount Sharp in the form of sediment deposits -- over a period of tens of millions of years. The finding suggests that lakes and rivers existed in many locations all over Mars.
"If our hypothesis for Mount Sharp holds up, it challenges the notion that warm and wet conditions were transient, local, or only underground on Mars," said JPL curiosity deputy project scientist Ashwin Vasavada. "A more radical explanation is that Mars' ancient, thicker atmosphere raised temperatures above freezing globally, but so far we don't know how the atmosphere did that."To read more, click here.