Deposits didn’t need flowing water to form, new research suggests
Ancient clay deposits on Mars may not indicate that the Red Planet was originally a warm, wet place, as scientists have thought. Instead of needing liquid water to form, many of Mars’ 4-billion-year-old clays could have originated from cooling lava, researchers report online September 9 in Nature Geoscience.
Clays are widely scattered across Mars’ oldest terrain, dating to the Noachian period 4.1 billion to 3.7 billion years ago. When the Mars Express and Mars Reconnaissance Orbiter discovered these minerals from orbit several years ago, geologists assumed the clays were a result of large bodies of water weat