Is there life on a distant planet? One way astronomers are trying to find out is by analyzing the light that is scattered off a planet’s atmosphere. Some of that light, which originates from the stars it orbits, has interacted with its atmosphere, and provides important clues to the gases it contains. If gases like oxygen, methane or ozone are detected, that could indicate the presence of living organisms. Such gases are known as biosignatures. A team of scientists from EPFL and Tor Vergata University of Rome has developed a statistical model that can help astronomers interpret the results of the search for these “signs of life”. Their research has just been published in Proceedings of the National Academy of Sciences (PNAS).
“Astronomers already use various assumptions to evaluate how credible life is on a given planet,” says Claudio Grimaldi, a scientist at EPFL’s Laboratory of Physics of Complex Matter (LPMC) who is also affiliated with the Enrico Fermi Research Center in Rome. “One of our research goals was thus to develop a method for weighing and comparing those assumptions in light of the new data that will be collected over the coming years.”