Search for Extraterrestrial Genomes

How can life theoretically be transferred between planets? How can we sample a very ancient environment by looking for life on Mars? Research Scientist at Massachusetts Institute of Technology Christopher Carr explains what metagenomic sequencing is.

The search for extraterrestrial genomes is a project to search for life beyond Earth. In particular, the most timely place that we might look for life might be Mars. And this project got started because of a series of studies that were carried out in the late 90’s. These studies revealed that there had been extensive transfer of rock between Earth and Mars due to large meteorite impacts.

It’s been shown that microbes can survive the kinds of shock pressures that would be encounter during a large enough impact event to eject material into space. It’s also been demonstrated that some of the material is ejected in the way that’s low temperature, so it wouldn’t be sterilized. Furthermore, it’s been shown that some of the material, a small fraction of the material can be carried between Earth and Mars over very rapid time scales.

In terms of surviving arrival at a new planet the speed at which these rocks would be travelling is such that they would go through the atmosphere very quickly, maybe under a few seconds, might be typical. In that context they would be heated in extraordinary amount, but only on the surface. So they would be burnt to a crisp on the surface, but inside they might still be at the temperature they were at in deep space which could be just a few kelvin.