Life: Definition, Origin, Criteria
... Collection of atoms Organic molecules • Where did life originate, on the Earth or extraterrestrial? • Have we been visited or are we the first? • Development of “intelligence” • Not all civilizations may (a) survive, or (b) explore and develop technology • Aliens in vastly different (a) forms of l ...
... Collection of atoms Organic molecules • Where did life originate, on the Earth or extraterrestrial? • Have we been visited or are we the first? • Development of “intelligence” • Not all civilizations may (a) survive, or (b) explore and develop technology • Aliens in vastly different (a) forms of l ...
Life on Titan
Whether there is life on Titan, the largest moon of Saturn, is at present an open question and a topic of scientific assessment and research. Titan is far colder than Earth, and its surface lacks stable liquid water; factors which have led some scientists to consider life there unlikely. On the other hand, its thick atmosphere is chemically active and rich in carbon compounds. On the surface there are bodies of liquid methane and ethane; some scientists speculate that these liquids might take the place of water in living cells different from those on Earth.In June 2010, scientists analysing data from the Cassini–Huygens mission reported anomalies in the atmosphere near the surface which could be consistent with the presence of methane-producing organisms, but may alternatively be due to non-living chemical or meteorological processes. The Cassini–Huygens mission was not equipped to look directly for micro-organisms or to provide a thorough inventory of complex organic compounds.A hypothetical cell membrane capable of functioning in liquid methane has been modeled.