Alien Genome Detection
Back on earth, a team of researchers at Harvard and MIT have initiated a project to study whether life on Earth might have descended from Martian organisms carried here by flying objects like meteors. Called the Search for Extraterrestrial Genomes (SETG), the project is based on evidence that viable microbes could have been transferred between the two planets.
As an example of the adaptability of microbial organisms, the team pointed to the discovery of the first known organism that can thrive and reproduce using arsenic instead of phosphorus in its cells. Last December, a NASA team isolated the bacteria from Mono Lake, CA, chosen because of its high salinity, alkalinity, and arsenic levels.
The NASA investigators said their data showed evidence for arsenate in macromolecules that normally contain phosphate, “most notably nucleic acids and proteins.” Such studies are changing our perception of what chemicals are needed for life and thus also our perception of what chemicals to look for on and around other planets.
The Harvard/MIT project will look for DNA and RNA through in situ analysis of Martian soil and ice samples. The team intends to use molecular biology approaches including PCR and to develop an instrument that can isolate, amplify, detect, and classify any extant DNA- or RNA-based organism, even at extremely low abundance.
Gary Ruvkun, Ph.D., professor of genetics, Harvard Medical School, explained in the team’s proposal that the group intends to develop an instrument that is “less than 5 kg and requires less than 10 Watts during any experimental run. We also propose to explore contamination-reduction protocols and to expand the DNA probes used to explore the boundaries of detectable life on Earth to maximize our chances of detecting life that is divergent from life on Earth.”