The Search for Life on Titan

While the first of Saturn’s moons to be discovered, Titan is actually the 20th farthest out from the ringed planet. Whether it’s distance from Saturn’s influence is partially responsible for it or not, the fact that Titan has the densest atmosphere of any moon in the solar system is reason enough for scientists searching for life to sit up and take notice. Add to this the fact that it is the only place in the solar system outside of Earth that has surface water and Titan becomes very important, indeed.

A Look at Titan

Titan is aptly named. Not only is it larger than the Earth’s moon and the sixth largest of Saturn’s moons to hold a spherical shape, this near-planet is actually larger than Mercury, although only about half as massive. Combining its size with its dense atmosphere, which prevented observation of the moon’s surface for a long time, and it is no wonder that Titan is thought of as a moon with many features of a planet.

Building a Case for Life

There are a number of reasons it is thought that Titan could possibly hold life on its far off surface. The atmosphere, composed largely of nitrogen, has a climate that is similar to earths in that it has wind, rain and clouds (although the clouds are composed of ethane and methane.) The climate has created features similar to Earth’s as well, but the similarity that has the scientific community most excited lies near Titan’s North Pole. Discovered in 2004 by the Cassini–Huygens mission are several large hydrocarbon lakes, the only such large and stable bodies of surface water known to exist in the solar system outside of Earth.

Some say this is reason enough to bend financial and intellectual resources to bring about a concentrated mission to Titan, and such may yet occur. The conditions on Titan have been compared to what a prehistoric Earth may have been like, albeit with a few important distinctions. This set of conditions has been called ripe for potential life, suggesting that Titan could be in the early stages of life evolution. With methane and nitrogen in the atmosphere it has been suggested that the origins of such gasses could be biological, but that is not necessarily so. In fact if life exists at all on Titan, some believe it may not have originated from the moon but from Earth itself.

Panspermia

Panspermia, or more commonly the expression “Exogenesis”, is the theory that the seeds of life existed elsewhere in the universe are were transferred to Earth at some point in the past. In the same fashion, during Earth’s creation and under the bombardment of asteroid and comet impacts, material from Earth could have been ejected into space and found its way to Titan, where the potential of life-friendly environments could have cultivated it.

Final Thoughts

Titan is home to the most remote landing by mankind ever made, when the Huygens portion of the Cassini–Huygens mission touched down on January 14, 2005. Evidence of water ice and surface water erosion has been confirmed, sparking more interest in further exploration.