Mars rover finds evidence that the red planet was once habitable

Nasa's Curiosity rover has found strong evidence that Mars was once habitable. Results of the most detailed analysis of the Martian atmosphere suggests that more than four billion years ago it was quite similar to Earth. via Pocket http://www.bbc.co.uk/news/science-environment-23370914#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa