Cassini finds hydrocarbon lakes at Titan’s south pole

William Atkins
Friday, 12 October 2007 18:35

Science - Space

The NASA Cassini spacecraft has begun to explore the south pole of Saturn’s moon Titan. So far it has discovered three lakes filled with liquid methane and ethane.            

NASA released on October 12, 2007, radar images taken by the RADAR instrument onboard the Cassini spacecraft of Titan’s south and north poles over the past one and one half years.

The Cassini spacecraft has discovered three new lakes near the south pole of Saturn's moon Titan. These strange bodies are filled not with water but liquid methane and ethane—types of hydrocarbons; that is, any organic compound made up of hydrogen and carbon. Methane has the molecular formula CH₄, while ethane has the formula C₂H₆.

Researchers are also studying a lake near Titan's north pole larger than Lake Superior on Earth.

The north pole of the moon Titan has been explored fairly extensively over the last 1.5 years. However, the south pole is only now being looked at by the Saturnian explorer. Its October 2, 2007 flyby of Titan’s south pole (called T36 flyby) discovered the three lakes when it passed within eighteen degrees of Titan’s south pole.

The lakes on Titan appear to vary in size. The smallest so far found is only about 0.4 square mile (1 square kilometer) in diameter while the largest one is over 40,000 square miles (100,000 square kilometers)—about the size of all of the Great Lakes in the central part of North America. Cassini scientists contend that such variance makes for a system similar to Earth’s water cycle, only with methane and ethane. Like rain falling to Earth, methane and ethane rain down on Titan, filling lakes and seas. Such bodies of methane and ethane then evaporate, form clouds, and more precipitation occurs—similar to climate conditions on Earth. So far, about 400 lakes have been discovered on Titan.

Cassini scientists have additional flybys of the south pole of Titan planned in the future.

The images taken by the Cassini spacecraft are found at The Planetary Society’s website “News flash: Lakes at Titan's south pole, too, on top of the land of lakes in the north”.