Life on Mars: Maybe it was underground
From “Did Life Once Exist Below Red Planet’s Surface? NASA Study of Clays Suggests Watery Mars Underground” (ScienceDaily, Nov. 2, 2011), we learn:
A new NASA study suggests if life ever existed on Mars, the longest lasting habitats were most likely below the Red Planet’s surface.
Discovery of clay minerals on Mars in 2005 indicated the planet once hosted warm, wet conditions. If those conditions existed on the surface for a long era, the planet would have needed a much thicker atmosphere than it has now to keep the water from evaporating or freezing. Researchers have sought evidence of processes that could cause a thick atmosphere to be lost over time.
This new study supports an alternative hypothesis that persistent warm water was confined to the subsurface and many erosional features were carved during brief periods when liquid water was stable at the surface.
“If surface habitats were short-term, that doesn’t mean we should be glum about prospects for life on Mars, but it says something about what type of environment we might want to look in,” …
Actually, it does probably mean we should be glum. Just not hopeless.