Early Life Or Just A Rock? Scientists Train Tool To Tell The Difference

It is the cloud that overshadows the search for alien life: for all the spacecraft sent to faraway worlds, researchers do not really know what to look for when it comes to evidence of life elsewhere.

- Ian Sample

Now, scientists have trained a computer program to distinguish chemical mixtures made by living organisms from those created in more prosaic processes, such as reactions between sunlight and rocks.

In preliminary tests, the program was 90% accurate at differentiating between samples taken from living organisms, such as shells, teeth and bones, and non-biological samples, such as laboratory chemicals and those found in carbon-rich meteorites.

These chemical "biosignatures" may be the best hope scientists have of finding past or present life.