The Search for Extraterrestrial Genomes
If there is life on Mars, Harvard geneticist Gary Ruvkun thinks it resembles something we are already familiar with -DNA. Now, he's trying to prove it for NASA, he reported yesterday to Boston.com
With early funding from NASA, Ruvkun is working on a sensor designed to test the soil of for DNA -the first part of a project he has dubbed the "Search for Extraterrestrial Genomes," which will be a part of a lander mission in the next decade.
Ruvkun points out that the project represents a stark break from the current operative philosophy of life detection: avoiding an Earth-centric view of what life might look like, which tainted earlier efforts.
Instead, inspired by evidence that microbes can shuttle between planets on meteors, Ruvkun argues it is most likely that any life on would be related to life on Earth and have somewhat similar DNA.
The project's prospects depend on a fascinating backstory: about 4 billion years ago the planets experienced a period of intense bombardment. Meteors came crashing down to the surface, ejecting more rocks into space, some of which came crashing down onto other planets. Life on Earth appeared very quickly after the bombardment -- to quickly, not to have been seeded, Ruvkun believes, by microbe-bearing meteors.
Martian rocks have been found on earth, and an analysis revealed that its core never experienced superheating as it fell to earth, showing that meteors could be viable shuttles for microbial life.
As we reported in Tuesday's post Extremeophiles, research has shown that there are microbes that have adapted to almost unbelievably extreme environments -- Extremophiles are the ultimate adventurers. These organisms thrive where other microbes don’t dare venture: boiling water holes, freezing lakes, and toxic waste dumps. Researchers have sequenced the genomes of two extremophiles that live at the bottom of Ace Lake in Antarctica, where there is no oxygen and the average temperature is a brutal 33 degrees below Fahrenheit.
As Ruvkun summed up for his Boston Globe feature: "Never bet against life." Read rest of the story...Posted by Casey Kazan
I would posit the existence of advanced sentient life forms on exoplanets where conditions are more generally considered inhospitable to life. Such life forms would constitute "extremeophile advanced forms of sentient life".
Posted by: Scott Smith | March 17, 2008 at 02:19 PM