usatoday:

This image of Mars is beautiful – and hugely exciting.

These dark, narrow, 100 meter-long streaks called recurring slope lineae flowing downhill on Mars are inferred to have been formed by flowing water – not in some dim, distant past, but as recently as last year. 

Until now, “we thought of the current Mars as a barren, extremely dry and cold desert,” SETI Institute planetary scientist Janice Bishop said. “What is new and exciting here is that this provides evidence for liquid water on Mars in the current environment.”

Read more: NASA finds evidence of recent flowing water on Mars