According to a new study conducted by NASA, the presence of abundant water on the surface of Mars was short lived, meaning any lifeforms probably lived within the planet and not on it.
In 2005, scientists discovered clay deposits on Mars' surface that indicated the presence, at one point, of water there. But after reviewing several years-worth of mineral-mapping data, NASA researchers have now determined that water on the planet's surface quickly disappeared due to the weak atmosphere.
That finding lends some credence to the theory that life on Mars may have existed underground, where evidence shows water supplies were protected from the thin atmosphere and thus more bountiful.
"The types of clay minerals that formed in the shallow subsurface are all over Mars," John Mustard, professor at Brown University and one of the study's co-authors wrote. "The types that formed on the surface are found at very limited locations and are quite rare."