Search for Life on Exoplanets
12 April 2016
Kepler Planets
Kepler Candidates for Life
Methane on Mars
Earth Spectrum
Summary
• A large fraction (1/6-1/4) of stars have Earth-size
planets
• Kepler has found about 50 planets in the
Habitable Zone
• To determine if a planet has life (biosphere) look
at light from it or visit it (far off!)
• IR light reveals temperature and composition
• Bio-signatures: compounds that provide evidence
of life: O, O3, CH4. Dis-equilibrium; vegetation
• If no bio-signatures, life is not necessarily absent