Does Earth have a Mars ancestry? We soon may know - CBS News
http://www.cbsnews.com/stories/2011/03/24/scitech/main20046689.shtml[3/24/2011 9:33:58 AM]
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March 24, 2011
Does Earth have a Mars ancestry? We soon may know
Device developed at MIT and Harvard could help determine if life on Earth came from Mars
By Mike Wall
(Space.com) It's possible that the family tree of all life on Earth
has its roots on Mars - and a new device could put that theory to
the test in a few years, researchers say.
Researchers are developing an instrument that would search
through samples of Martian dirt, isolating any genetic material from
microbes that might be present - bugs that are living or that died
relatively recently, within the last million years or so. Scientists
could then use standard biochemical techniques to analyze any
resulting genetic sequences, comparing them to what we find on
"It's a long shot," said MIT researcher Chris Carr, who's working on
the life-detecting device, in a statement. "But if we go to Mars and
find life that's related to us, we could have originated on Mars. Or if
it started here, it could have been transferred to Mars."
Either way, Carr added, "we could be related to
life on Mars
. So we
should at least be looking for life on Mars that's related to us."
Ancient Martian life?
The idea that all Earth life could be descended from Martian
organisms may not be fully mainstream - but it's not too crazy to
dismiss, either. While the Martian surface appears to be cold, dry
and lifeless today, there is plenty of evidence that the planet was
much warmer and wetter in the distant past, billions of years ago.
Here on Earth, life almost invariably occupies any niche that contains liquid water. So ancient Mars may have once
supported some form of life - perhaps even before Earth did, researchers said.
If that's the case, these
may have colonized Earth, zipping through interplanetary space aboard rocks
blasted off the Martian surface by asteroid impacts. An estimated 1 billion tons of Martian rock have made this journey
over the years, researchers said.
And microbes are incredibly hardy, so it's possible that some bugs could have survived the asteroid impact and the
trip through space to a new planet, they added. Orbital dynamics show that it's about 100 times easier for rocks to
travel from Mars to Earth than the other way around, Carr said.
So if life got started on Mars first, it's possible that every living thing on Earth can trace its lineage back to a Martian.
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