Researchers studying soil samples collected by NASA's Phoenix Lander three years ago say that while Mars was warmer and wetter early in its history, the surface has suffered a "super drought" for the past 600 million years that makes today's surface inhospitable to life.
They looked for evidence that the soil had interacted with water, such as the presence of particles of clay. In fact, extremely small amounts of clay were found. Scientists estimate that in the billions of years of Mars history the surface has been exposed to water for a total of perhaps only 5,000 years.
Mars may still harbor life, but if it does, that life almost certainly exists well beneath the surface, where Mars also has tons of water ice.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment