Minerals found in the subsurface of Mars, a zone of more than three miles below ground, make for the strongest evidence yet that the red planet may have supported life (NOTE: Subscribers can still listen to this show).
Up to half of all life on Earth consists of simple microorganisms hidden in rocks beneath the surface and for some time, scientists have suggested that the same may be true for Mars. Now this theory has been supported by new research, which suggests that the ingredients for life have been present in the Martian subsurface for much of the planet's history.
When meteorites strike the surface of Mars, they act like natural probes, bringing up rocks from far beneath the surface. Recent research has shown that many of the rocks brought up from the Martian subsurface contain clays and minerals whose chemical make-up has been altered by water, an essential element to support life. Some deep craters on Mars also acted as basins where groundwater likely emerged to produce lakes.
McLaughlin Crater is one such basin that contains clay and carbonate minerals formed in an ancient lake on Mars. The fluids that formed these minerals could carry clues to as to whether the subsurface contained life. Planetary geologist Joseph Michalski says, "We don't know how life on Earth formed but it is conceivable that it originated underground, protected from harsh surface conditions that existed on early Earth. Due to plate tectonics, however, the early geological record of Earth is poorly preserved so we may never know what processes led to life's origin and early evolution."
Geochemist John Parnell says, "We know from Earth's history that planets face traumatic conditions such as meteorite bombardment and ice ages, when the survival of life may depend on being well below ground. So it makes sense to search for evidence of life from that subsurface environment, in the geological records of both Earth and Mars. But it's one thing to do that on Earth--we need to be clever in finding a way to do it on Mars." Shovels, anyone?
MOTKE told Whitley why we're not up there on the Red Planet with shovels right now: He said the parents of the child who would have discovered the secret to gravity that would give us access to space were killed in the holocaust!