March 23, 2011 at 3:55 PM ET
Life as we know it has a common ancestor — somewhere. Is it a Martian? A new device under development to fly on a future mission to Mars to find and sequence bits of genetic material could provide an answer, according to MIT and Harvard scientists.
"Given what we know about meteorite impacts and transfer of material between Earth and Mars, we are hoping that life may in fact exist on Mars and that it may in fact be related to us," Christopher Carr, a MIT research scientist who is leading the project, told me today.
The idea that life originated on Mars goes back before the Viking missions of the 1970s, which looked for signs of life on the Red Planet. It got a boost in the 1990s with the discovery that microbes could have hitched interplanetary rides on meteorites between the two planets during an intense period of bombardment between about 3.5 and 4 billion years ago.
"About a billion tons of rock probably went between Earth and Mars, most of that actually went in the Mars-to-Earth direction — about a 100-fold higher amount," Carr noted. "So that makes it more likely that if we find something on Mars that's related to us that it actually came from Mars to Earth."
Carr and colleagues have identified regions of genome sequences that are conserved across all known life forms on Earth and are working on a device that will look for bits of this genetic material on Mars.
The device, called the Search for Extra-Terrestrial Genome (SETG), will isolate any RNA or DNA from bits of soil, rock and ice brought up from the subsurface of Mars, amplify it to the point it could be detected and then sequence it.
So far their prototype consists of the micro-fluidic chip in the image above which can amplify and detect bits of genetic material. In the next few years, they aim to add components to isolate the genetic material and sequence it as well.
"Our hope is that in the next two years, we will have a system that we can put in soil at the beginning and get sequences out at the end," he said. The aim is for an instrument that weighs about 2 kilograms and is roughly the size of a shoebox.
Finding genetic material on Mars that shows a link with life on Earth would allow scientists to learn more about how we are related and when the split occurred. As for whether the scientists will have any luck finding genetic material that shows we're all Martians remains an open question.
"I think it is entirely possible," Carr said. "I wouldn't necessarily say probable. Bottom line, if it is there, we want to find it. It may or may not be."
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