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Moon and Saturn

January 15, 2015

The largest known reservoir of hydrocarbons isn’t in Texas, the oil sands of Alberta, or even the Persian Gulf. It sits on the surface of Titan, the largest moon of Saturn.

The regions around Titan’s poles are speckled with lakes and seas. The largest are bigger than some of the Great Lakes. But Titan is so cold that water is frozen as hard as granite. So instead, the lakes and seas are filled with methane and ethane — liquid hydrocarbons — compounds that are similar to those that make up petroleum and natural gas.

The Cassini spacecraft has used radar to probe deep into a few of the lakes and seas. It’s recorded depths of up to several hundred feet.

That’s allowed scientists to calculate the volume of Ligeia Mare, one of the largest seas. It contains about three times as much liquid as Lake Michigan — and about 55 times as much liquid hydrocarbons as all the known oil deposits on Earth.

The sea with the greatest surface area is Kraken Mare. Cassini measured the depth of a narrow inlet at about a hundred feet. But it couldn’t see the bottom of most of Kraken. That could mean that it’s deeper than Cassini’s radar can probe — more than 600 feet. If so, then Kraken would contain even more hydrocarbons than Ligeia.

Saturn is in good view at dawn tomorrow. It looks like a bright star just a degree or so from the Moon. Titan is visible through a small telescope — a tiny dot near Saturn that’s the solar system’s biggest gas station.


Script by Damond Benningfield, Copyright 2014

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