Titan: Thar's Oil in That Thar Moon

Feb. 14, 2008 -- Worried about Earth running out of natural gas? Scientists have found a place that makes Earth's supplies look like drop in a bucket.

The only problem is the reservoirs are located about 750 million miles away on Saturn's moon Titan.

"It's really just kind of a fun fact," planetary scientist Ralph Lorenz with Johns Hopkins University Applied Physics Laboratory told Discovery News.

Lorenz and colleagues calculated the amount of liquid hydrocarbons on Titan using radar data gathered from the orbiting Cassini spacecraft. With about 20 percent of the moon mapped, scientists have found several hundred lakes and seas dotting Titan's surface.

Extrapolating from lake depths on Earth, the researchers estimate several of the lakes on Titan each contain more than the total amount of natural gas on Earth, estimated to be about 130 billion tons. That means the orange moon has hundreds of times more liquid hydrocarbons than all the known oil and natural gas reserves on Earth.

While it may be implausible to tap Titan's reserves, the research has implications for understanding Earth in its primordial stages since it likely resembled Titan.

One puzzle scientists are trying to figure out is why Titan has so much methane in its atmosphere. The gas breaks down in ultraviolet light from the sun, leading scientists to wonder how methane is being resupplied into the moon's atmosphere.

Lorenz' study, which was published in the Jan. 29 issue of Geophysical Research Letters, shows there is not enough sources of methane on the ground to account for the atmospheric levels.

That leaves two options: a subterranean source exists that is periodically tapped by volcanic eruption, for example; or Titan is undergoing or has undergone a relatively short-lived phenomenon that triggered a methane release.