LICHENS and algae could be the first life forms we find on Earth-like exoplanets, by looking for their light signatures in a planet’s distinctive colouring.
Seen from space, Earth gives off a large amount of near-infrared light, which is reflecting off the chlorophyll in plants. As telescopes get more sensitive, it should be possible to see a similar “red edge” on distant exoplanets if they also host green vegetation.
But Siddharth Hegde and Lisa Kaltenegger of the Max Planck Institute for Astronomy in Heidelberg, Germany, think it is possible that many rocky worlds will have extreme heat, dryness or…
