Friday, November 09, 2012

Reader EJ brings up a good question: If methane is a fossil fuel, what's it doing on Saturn's moon Titan?

June 2012: Huge Tropical Methane Lake on Saturn Moon Titan |
An oasis of liquid methane has unexpectedly been discovered amid the tropical dunes of Saturn's moon Titan, researchers say.
Methane - Wikipedia, the free encyclopedia
Methane ... is a chemical compound with the chemical formula CH4. It is the simplest alkane, the main component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel.


NiV said...

Methane reacts with oxygen - it is only abundant on Titan because there's no oxygen there. On Earth any native methane was oxidised long ago, and the vast majority is formed by bacteria living in low-oxygen conditions.

Methane as a substance is not *inherently* fossil, but on Earth it mostly is.

Anonymous said...

You mean all the methane locked up in the clathrates were formed by bacteria?

NiV said...


99% of it in the deep formations is produced by hydrogeonotrophic methanogens (a type of bacteria) from H2 and CO2. It then seeps up through cracks in the rock until it hits either very cold or deep water. There's a small fraction formed by breakdown of buried organic matter under heat. And around deep water oil/gas wells leakage can form clathrate deposits.