Biosignatures & Paleobiology: February 2020

Can multicellular life be distinguished from single cellular life on an exoplanet? We hypothesize that abundant upright photosynthetic multicellular life (trees) will cast shadows at high sun angles that will distinguish them from single cellular life and test this using Earth as an exoplanet.

Scientists have discovered thousands of exoplanets, including dozens of terrestrial -- or rocky -- worlds in the habitable zones around their parent stars.

Over the last several years, spectroscopic observations of transiting exoplanets have begun to uncover information about their atmospheres, including atmospheric composition and indications of the presence of clouds and hazes.