ASTRONOMY - In a new study published in The Astrophysical Journal, astronomers propose looking for greenhouse gases in the atmospheres of exoplanets using tools like the James Webb Space Telescope (JWST). But rather than searching for an advanced species suffering the consequences of climate change, such gases might be a sign of something else: terraforming.
Terraforming is a hypothetical concept involving taking an inhospitable place or planet — like Venus or Mars — and making it more suitable for life by radically altering its atmosphere or temperature. (Think Total Recall or Star Trek III: The Search for Spock.)
In this case, the astronomers suggest that greenhouse gases may have changed a planet that would otherwise be too cold for life as we know it in a way that would give it more comparatively tropical temps. The astronomers knew that some civilizations would produce chlorofluorocarbons (CFCs), groups of chemicals that, on Earth, contribute to climate change. They’re highly reactive but also dissipate quickly, so the researchers looked for more stable and effective chemicals.
“A long-lived intelligent civilization may only maintain high levels of harmful atmospheric pollution for a short time,” study author Edward W. Schwieterman of the University of California, Riverside says. “So we asked, what would be an example of an atmospheric technosignature (a signal of something that could only be produced by technology) where there would be an incentive to maintain those technosignatures for long time scales?”