Ralph Lorenz, Cassini radar team member from the Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, led the study. "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," he added. Cassini has mapped about 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 Earth's oil and gas reserves.
In fact, the dark dunes that run along the equator contain a volume of organics several hundred times larger than Earth's coal reserves.
Though proven reserves of natural gas on Earth total 130 billion tons, enough to provide 300 times the amount of energy the entire United States uses annually for residential heating, cooling and lighting, dozens of Titan's lakes individually have the equivalent of at least this much energy in the form of methane and ethane.
According to Lorenz, "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 yet know how much liquid is there."
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 on Feb. 22, when the radar instrument will observe the Huygens probe landing site.