AST101H1 Lecture Notes - Lecture 12: Earth Similarity Index, Terrestrial Planet, Exoplanet

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Bryan Gaensler

Document Summary

abiogenesis: life arose on earth through natural processes that converted inorganic material into the first simple life forms. panspermia: life is everywhere in the universe and is transported to new planets on asteroids, comets, etc. In our solar system, we can figure out if a moon has water beneath its surface. For exoplanets (or exomoons) we can"t determine this -only consider surface water. Habitable zone: orbits where a terrestrial planet could have liquid water on its surface. We have found many terrestrial exoplanets in the habitable zone. Rates an exoplanet"s similarity to earth in terms of size, density, escape velocity, and temperature. Search for other intelligent civilizations by looking for their radio transmissions or optical transmissions. Can only see about 100 light years out. Can"t be that hard for life to start. Civilizations have had plenty of time to explore. Everyone is listening, no one is talking (scared)