Finding Life Beyond Earth

[Jim Colyer]

http://www.youtube.com/watch?v=OYXUWJ0_ncw

Scientists search the solar system for places where life might exist. Mercury and Venus are too hostile. Mercury is basically a ball of iron, the core of a planet. The three ingredients making life possible on Earth are energy from the sun, water and organic compounds (those containing carbon, oxygen, hydrogen and nitrogen). Planet formation is discussed, and the possible role of comets. Comets contain amino acids, the seeds of life. It is believed that water once flowed on Mars, and one guy calls Mars an ice cube covered with dirt. These people desperately want to find extraterrestrial life while Curiosity roams Mars looking for organic molecules. Further out, it is hinted that Jupiter's moon Europa may harbor life in oceans beneath its ice. Finally, it is suggested that Saturn's moons Enceladus and Titan may have internal energy sources. Titan has lakes of liquid methane, and astrobiologists wonder whether different kinds of life might form in liquids other than water. Planet-hunter Geoff Marcy closes the show. From TV's Nova.