When scouting for life on exoplanets, how do we know where to start? With an inventory of more than 5,000 confirmed exoplanets (according to NASA) and counting, searching one by one can be difficult. So scientists are working to devise a method to determine what features of an exoplanet’s atmosphere might indicate life. 

It’s a tricky task, because a planet’s evolution can affect what gases are present in its atmosphere. On Earth, for example, plate tectonics make volcanoes possible, which bring gases from the interior into the atmosphere. So scientists use models to simulate geological cycles to learn to recognize which atmospheric conditions suggest which types of planetary evolution. 

In her dissertation research, Earth and planetary sciences doctoral candidate Junellie Perez is working to push the boundaries of what we can observe with telescopes by connecting models of geological evolution and observational findings. Eventually, such models could help scientists categorize when certain gas signatures are expected with plate tectonics, for example, and when they could be a clear indication of life.