The hunt for extraterrestrial life on distant planets may be operating with a big blind spot. That's because we aren't accounting for the nature of the light coming from the host star itself when we interpret the chemical signatures of life, or biosignatures, on some of the most promising candidate planets beyond the solar system. If we don't consider that crucial factor, we could be led on a wild-goose chase across the cosmos.Despite having discovered thousands of exoplanets, we have not detected convincing evidence of alien life on any of them. But astronomy is reaching a point where powerful telescopes can zoom in on many more potentially habitable worlds. Planets that orbit M dwarfs, whi...