Science fiction has given us many stories about microbes from other worlds decimating life on Earth. And in fact, when the first Apollo astronauts returned from the Moon, they were held in quarantine for weeks to make sure they weren’t infected with lunar bugs.
Scientists aren’t just concerned with protecting Earth against alien life, though; they’re also concerned with protecting other worlds against life from Earth.
Consider, for example, Mars Science Laboratory, a rover that’s awaiting launch. It’s the most impressive Mars lander to date. It’s as big as a car, weighs almost a ton, and carries a sophisticated suite of instruments. It’s powered by a nuclear generator that should allow it to travel long and far and dig deep into the secrets of life on Mars.
But scientists want to make sure that if it finds evidence of life, it’s of the Martian variety, and not hitchhikers from Earth. So the rover was assembled in cleanrooms in which bacteria were filtered from the air. Its surfaces were thoroughly cleaned, and some parts were heated above the boiling point of water. Others were tightly sealed to keep any “germs” inside.
Any bacteria that do accompany the rover will be zapped by solar and cosmic radiation during the trip. And the rover’s exterior will be bathed in ultraviolet radiation from the Sun every day. Even so, it’s possible that some bacteria could survive — and perhaps establish a colony on another world.
Script by Damond Benningfield, Copyright 2011
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