Mars H2O: How Scientists Discovered Salty Water on the Red Planet

This week's announcement that salty liquid water flows on Mars has reinvigorated debates about whether the Red Planet's environment could support life. Scientists announced yesterday (Sept. 28) that dark, narrow streaks that appear on Mars are caused by flowing water. The mysterious streaks were first spotted on the planet in 2011, but it was the chemical signature of the enigmatic lines that helped researchers make their discovery.