Water on Mars: Nasa reveals briny flows on surface - as it happened

Nasa confirm discovery of summer watery flows on planet's surface down cliffs and crater walls raising odds of finding life on red planet

• Nasa scientists find evidence of flowing water on Mars
• Water on the red planet - in pictures
• A visual guide to water on Mars

6.08pm BST

We're going to close out our live coverage of today's Mars water announcement with an audio clip from Nasa's Dr Jim Green. Speaking at the press conference in Washington DC, he described how our understanding of the red planet is changing.

Thanks for being with us today for this news, which may just make sending astronauts to Mars a lot easier.

5.49pm BST

So the news is that there is flowing water on Mars. The evidence comes from dark streaks that appear on the surface of the Red Planet. These have been known about for many years because the landscape has been seen to change on successive images taken by spacecraft orbiting Mars. Although flowing water has always been a possibility for their creation, other ideas such as the movement of dry ice (carbon dioxide) or the action of the wind, could not be ruled out.

Now, however, strong evidence for them being driven by water has been collected by an instrument called CRISM on board Nasa's Mars Reconnaissance Orbiter. It has seen the signature of salts known as perchlorates in the dark streaks. These indicate that flowing salty water is responsible for the markings.