Planet’s Glow May Shine Light on Possible Life

Earthshine is the sunlight that is reflected off Earth and reflected back by the moon, and while it may seem like this is simply just a pretty glow to be seen from other positions of the universe, some astronomers believe the shines of exoplanets could speak wonders about its potential for life.

These glows emitted by planets display imprints of the chemicals present in their atmospheres and the materials on the surface (as plants and rocks do not reflect light similarly). However, with their parent stars’ shines being infinitely brighter, detecting minuscule variations in glow within an exoplanet poses a dilemma.

By using a large telescope to examine our own polarized earthshine, Michael Sterzik and colleagues of the European Southern Observatory in Santiago, Chile, were able to distinguish the polarized light of planets from the unpolarized stars filling the sky. Through this team’s testing, they were able to confirm the technique’s accuracy, as their results concluded that Earth had “light signatures of oxygen, ozone and water, as well as an increase in reflected wavelengths characteristic of vegetation.” With even larger telescopes pointed outward, looking for these characteristics among exoplanets should be a viable possibility.