Mars Had Liquid Water On Its Surface. Here's Why Scientists Think It Vanished
A new study indicates that the relatively low mass of Mars allowed most of its water to be lost to space billions of years ago, rather than retained on its surface.
All evidence points to the fact that Mars once had flowing water, but numerous flybys, orbiters, landers and rovers have confirmed one undeniable fact — any liquid water that was once on its surface is now long gone.
A out of Washington University in St. Louis might have found the reason: Mars, which is about half the size of Earth, and just over one-tenth the
