The first time we find evidence of life on a planet orbiting another star (an exoplanet), it is probably going to be by analyzing the gases in its atmosphere. With the number of known Earth-like planets growing, we could soon discover gases in an exoplanet’s atmosphere that are associated with life on Earth.
But what if alien life uses somewhat different chemistry to ours? A new study, published in Nature Astronomy, argues that our best chances of using atmospheres to find evidence of life is to broaden our search from focusing on planets like our own to include those with a hydrogen atmosphere.
…
The authors carried out laboratory experiments in which they demonstrated that the bacterium E. coli (billions of which live in your intestines) can survive and multiply under a hydrogen atmosphere in the total absence of any oxygen. They demonstrated the same for a variety of yeast.
Share this article
…
The researchers demonstrated that there is an “astonishing diversity” of dozens of gases produced by products in E. coli living under hydrogen. Many of these, such as dimethylsilfide, carbonyl sulfide, and isoprene, could be detectable “biosignatures” in a hydrogen atmosphere. This boosts our chances of recognizing life signs at an exoplanet; you have to know what to look for.
