View Full Version : The Source of Titan's Methane

2006-Mar-03, 12:56 AM
SUMMARY: Titan is unique in the Solar System with its methane rich atmosphere. But where does all this methane come from? Scientists analyzing data returned by ESA's Huygens probe think it's being replenished by a layer of methane ice underneath the surface. They believe this crust of methane is floating on top of an ocean of liquid water mixed with ammonia. This ongoing out gassing of methane probably peaked hundreds of millions of years ago, and now it's on a slow, steady decline.

View full article (http://www.universetoday.com/am/publish/source_titans_methane.html)
What do you think about this story? post your comments below.

2006-Mar-03, 09:33 AM
Duh so where does the methane "ice" come from?

2006-Mar-13, 12:31 PM

Methane has been found widely in various molecule clouds in space. These clouds are the birth places of stars, and when our solar system was born in such a cloud some five billion years ago, methane was there, too.

As methane seems to play a role on Titane similar to the role water plays on Earth, it is reasonable to accept a methan cycle on Titan: Some process releases methane from methane-containing ice (like the warmth of the sun does with water from damp ground on Earth), the methane gets into the atmosphere, some of this methane is destroyed by solar UV radiation (as does the the sun with water molecules in the high atmosphere on Earth), the fragments of the broken methane molecules combine to new, larger organic molecules (called 'tholine') which is responsible for the color of Titan´s atmosphere. The tholine builds larger particles which gradually settle to the ground. Some of the methane condenses to droplets which build clouds, from which finally falls a rain of liquid methane. This rain washes the tholine particles from the rocky surface down into the river channels (which we see on the Huygens pictures) and deposits them there.

To me, the river beds on Titan show a pattern which looks like as if caused by rain floods. They extend over a rather vast area, much wider than the area heated by a volcano. A spring well would not be able to wash the tholine from the hills, as a spring well flows in the river bed, and not from the crest of the hills.