When searching for signs of life on planets outside our Solar System, sometimes nothing is almost as good as something. Even a lack of biosignatures on examined exoplanets can still tell us a lot about the probability of life on the billions of planets we haven’t checked out yet, according to a study in The Astronomical Journal.
The study employed a sophisticated statistical analysis to determine the minimum number of exoplanets that would need to be observed to generate useful answers about how many potentially inhabited planets are out there. They determined that finding no signs of life on 40 to 80 exoplanets would not, in fact, rule out that such life exists. Instead, such an answer would only whittle down the probability a bit.
