Scientists Want to Study Exoplanet Atmospheres for Signs of Alien Life
Most exoplanet hunting telescopes are only able to tell basic things about a planet like its mass or distance from its host star, but a new generation of exoplanet telescopes like PLATO promise to reveal their subjects detail, including the composition of their atmospheres. The question, then, is what sorts of atmospheric markers would indicate the presence of extraterrestrial life? In a new paper published Wednesday in Astrophysical Journal Letters, University of California-Riverside planetary scientist Stephanie Olson outlined a dynamic framework for detecting life based on how the composition of exoplanet atmospheres change during the seasons.
The model is based on Earth’s own atmospheric seasons, which change as the Earth rotates on its axis. For example, during the summer the composition of the northern hemisphere’s atmosphere shows a marked rise in oxygen and a corresponding decrease in carbon dioxide because of all the plant growth. Olson argues that similar signatures could reveal the presence of life on other planets.