A River Ran Through It: Why Do They Think There Was Once Water on Mars?

This week's big news was the announcement of

evidence for flowing water on Mars

, based on images of what appear to be smooth river rock-type pebbles found by Curiosity. Of course that's a big statement to make, and for good reason -- identifying water, whether present or past, is one step closer to determining whether Mars was ever a suitable place for life to develop. Yet here we are, not even two months into the mission and Curiosity is already sending us solid clues that Mars was once a much wetter place than it is now.

JPL released a video today providing a brief-but-informative overview of what Curiosity has discovered in Gale Crater and why it's gotten everyone so excited.

Check it out so you'll have something to talk about over the weekend:

Video: JPLNews. Images: NASA/JPL-Caltech