Title: Finding Signs of Life in Transit: High-resolution Transmission Spectra of Earth-like Planets around FGKM Host StarsAuthors: Lisa Kaltenegger, Zifan LinFirst Author’s Institution: Cornell University & Carl Sagan Institute, Ithaca, New York, USAStatus: Published in ApJ [closed access]
Figure 1: An artist’s impression of an inhabited waterworld, basking in the glow of its low mass starCredit: Amanda Smith, University of Cambridge
ANYBODY OUT THERE?One of the most fascinating topics in astronomy and maybe in philosophy itself, is the potential existence of other life out there in space. Strange planets, orbiting other stars, developing and evolving their own biology under unique circumstances. Fortunately life leaves signatures, so-called biosignatures, for the keen observer to find. Most prominently so, biosignatures are left in the atmosphere of an inhabited planet. The presence of certain substances and molecules in an atmosphere suggests biological processes indicative of life. For instance, life creates large amounts of molecular oxygen (O2) by photosynthesis and small amounts of methane (CH4) on Earth. The simultaneous presence of these two molecules are strongly suggestive of biological processes, since on short timescales, these two species react to create carbon dioxide (CO2) and water (H2O) and must therefore constantly be replenished to remain ...