By Xinhua
Washington : Saturn’s orange moon Titan has hundreds of times more liquid hydrocarbons than the known oil and natural gas reserves on Earth, according to new data from NASA’s Cassini spacecraft.
The hydrocarbons rain from the sky, collect in vast deposits that form lakes and dunes. The new findings from the study led by Ralph Lorenz, a Cassini radar team member from the Johns Hopkins University Applied Physics Laboratory, are reported in the latest issue of the Geophysical Research Letters Wednesday.
“Titan is just covered in carbon-bearing material. It’s a giant factory of organic chemicals,” said Lorenz. “This vast carbon inventory is an important window into the geology and climate history of Titan.”
Titan is very different from Earth. Instead of water, liquid hydrocarbons in the form of methane and ethane are present on Titan’s surface, and tholins probably make up its dunes.
The term “tholins” was coined by Carl Sagan in 1979 to describe the complex organic molecules at the heart of prebiotic chemistry.
Cassini has mapped around 20 percent of Titan’s surface with radar. Several hundred lakes and seas have been observed, with each of several dozen estimated to contain more hydrocarbon liquid than the Earth’s oil and gas reserves.
The dark dunes that run along the equator contain a volume of organics several hundred times larger than Earth’s coal reserves.
Proven reserves of natural gas on Earth total 130 billion tonnes. Dozens of Titan’s lakes individually have the equivalent of this energy in the form of methane and ethane.
“This global estimate is based mostly on views of the lakes in the northern polar regions. We have assumed the south might be similar, but we really don’t know how much liquid is there,” said Lorenz.
Cassini’s radar has observed the south polar region only once, and only two small lakes were visible. Future observations of that area are planned during Cassini’s proposed extended mission.
Cassini’s next radar flyby of Titan is Feb 22, when the radar will observe the Huygens probe landing site.