Astrobiology: Looking at Saturn's moon: Titan

Astrobiology is the study of the origins, evolution, distribution, and future of life in the universe. Requiring fundamental concepts of life and habital environments and embraces the search for potentially inhabited plantes beyond our Solar System.

Mythology of Titan: "The Titans are the ancestors of the human race. The Titans devoured the limbs of Dionysus, the son of Zeus, who intended the child to have dominion over the world. Enraged, Zeus struck the Titans with lightning. The fire burned them to ashes, and from the ashes man was formed."

Average Distance from Saturn: 1,221,830 km

Titan's surface temperature: -178C (-289F)

Atmospheric pressure: near the surface is about 1.6 bars, 60 percent greater than Earth's

Equatorial radius: 2,575km (1,600 miles)

Mass: 134,550,000,000,000,000,000,000kg

Titan orbits Saturn at a distance of: 1.2 million km ( 745,000 miles) taking 15.94 days to complete a full orbit

Atmospheric Constituents: Nitrogen, Hydrogen, and Carbon: N2, CH4

Titan was discovered by a Dutch astronomer named Christian Huygens in 1655, Titan is the largest moon out of the 56 known moons orbiting Saturn. Titan is of great interest to scientists because it is the only moon in the solar system known to have clouds and a mysterious, thick, planet-like atmosphere.

Titan is similar in bulk composition to Ganymede, Callisto, Triton, and (probably) Pluto about half water ice and half rocky material. Its interior may still be hot, similar to Saturn's other moons it is however denser because it is so large that its gravity slightly compresses its interior.

The hydrocarbon rich elements are the building blocks for amino acids necessary for the formation of life. Scientists believe that Titan's environment may be similar to that of the Earth's before life began putting oxygen into the atmosphere. Titan is the only moon in the solar system with a significant atmosphere, in fact Titan's atmospheric pressure is about 1.6 times that of Earth. Titan's surface is almost entirely hidden by its atmosphere, a thick red haze that in some ways resembles the smog found on Earth. It is composed primarily of molecular nitrogen as does Earth, with no more than 6% argon and a few percent methane. There is clear evidence for "precipitation, erosion, mechanical abrasion and other fluvial activity." Life could exist in the deep interior of Titan where liquid water may be available all the time, if it is hosts such volcanic processes, then water exists temporarily on the surface, potentially hosting life. The Cassini spacecraft, which began orbiting Saturn in the summer of 2004, carried cloud penetrating radar and other instruments designed to see through the thick atmosphere. It also carried a probe called Huygens that was designed to drop through Titan's atmosphere and land on its surface. In January of 2005, the Huygens probe actually landed on Titan and sent back images from the surface.

Huygens three discovered evidences:

Lakes on Titan? Scientists speculated that liquid methane or ethane might form lakes on Titan, particularly near the somewhat colder polar regions. In the images a variety of dark patches some with channels leading in or out of them appear. The channels have a shape that strongly implies they were carved by liquid. The abundant methane in Titan's atmosphere is stable as a liquid under the tight conditions as is its abundant chemical product ethane but liquid water is not. Scientists interpret the dark areas as lakes of liquid methane or ethane making Titan the only body in the solar system besides earth known to possess lakes.

Evidence of a shoreline? The boundary of the bright region and the dark region appears to be ahoreline. The patterns in the dark area indicate that it may once have been flooded with the liquid having at least partially receded.

Dune fields on Titan? Prominent dark areas found in the moon's equartorial region appear to contain vast and continuous dune fields discovered by the Cassini Radar experiment and likely composed of particles that drop from Titan's unique smoggy atmosphere.

Interesting evidence that could possibly be linked to life forming on Titan.

Lake formations on Titan seen by Huygen

Shoreline patterns on Titan, separation of dark and light shading

Sand Dunes in the moon's equatorial region

Web site created by: Suzanne Crosgrove, Brittany Sturrock, and Cera Adams

Created December 2, 2006

References:

Burnham, Robert, "Hubble Maps Titan's Hidden Landscape, " Astronomy, 44-45, February 1995

http://www.solarviews.com/eng/titan.htm

Porco, Carolyn. "Titan." World Book Online Reference Center. 2005. World Book, Inc.

http://www.worldbookonline.com/wb/Article?id=ar559220

For more information about Cassini-Huygens mission visit

http://saturn.jpl.nasa.gov

http://solarsystem.jpl.nasa.gov/planets/profile.cfm?Object=Sat_Titan

http://solarsystem.jpl.nasa.gov/planets/profile.cfm?Object=Sat_Titan&Display=Facts&System=Metric

http://solarsystem.nasa.gov/missions/profile.cfm?Sort=Planets&Object=Saturn&Mission=Voyager_1

http://www.seds.org/nineplanets/nineplanets/titan.html

http://www.solarviews.com/eng/titan.htm

http://www.spacedaily.com/news/saturn-titan-04t.html

http://www.nasa.gov/mission_pages/cassini/Saturns_Moons_2.html