Just How Significant Is Methane On Titan?

Sep 12, 2005

Titan's second most abundant constituent, methane, is critical to the maintenance of an earth-like nitrogen atmosphere on this satellite. Without methane, Titan's nitrogen would condense, leaving behind a puny amount in the atmosphere.

Source of Titan's methane

The Sun's ultraviolet light should have destroyed methane in approximately ten million years-a fraction of Titan's age. Some process must be producing methane lost to photolysis. Unlike the deep, dense atmospheres of the giant planets where the photoproducts of methane are cooked in their hydrogen-rich interiors to produce methane back, photoproducts of Titan's methane do not meet the same fate.

Hence, methane came in as methane clathrates during Titan's formation, or it is manufactured in situ in Titan's interior. Noble gas data tend to favor the latter process that is based on serpentinization.

I consider low temperature serpentinization as a very promising source of methane on Titan. It occurs in terrestrial oceans, e.g. in Lost City 15-20 km from spreading centers where Black Smokers are sighted.

The process involves water-rock reactions. The type of rocks and temperatures needed are expected to exist in Titan's interior also.

In this process, hydrogen (H2) is released in the hydration of iron or magnesium rich rocks (ultramafic silicates), and this H2 then combines with carbon dioxide or carbon in crustal pores to produce methane. Methane so produced could be "stored" as clathrate in Titan's interior for later release to the atmosphere, or the process could be going on even now.

Biology as a source of methane on Titan is not supported by the data.

Copyright 2005 by Space Daily, Distributed United Press International

Explore further: Researchers discover low-grade nonwoven cotton picks up 50 times own weight of oil

add to favorites email to friend print save as pdf

Related Stories

Titan offers clues to atmospheres of hazy planets

Jul 28, 2014

When hazy planets pass across the face of their star, a curious thing happens. Astronomers are not able to see any changes in the range of light coming from the star and planet system.

Titan's building blocks might pre-date Saturn

Jun 24, 2014

(Phys.org) —A combined NASA and European Space Agency (ESA)-funded study has found firm evidence that nitrogen in the atmosphere of Saturn's moon Titan originated in conditions similar to the cold birthplace ...

Mysterious 'Magic Island' appears on Saturn's moon Titan

Jun 22, 2014

Now you don't see it. Now, you do. And now you don't see it again. Astronomers have discovered a bright, mysterious geologic object – where one never existed – on Cassini mission radar images of Ligeia ...

Recommended for you

Fermi satellite detects gamma-rays from exploding novae

13 hours ago

The Universe is home to a variety of exotic objects and beautiful phenomena, some of which can generate almost inconceivable amounts of energy. ASU Regents' Professor Sumner Starrfield is part of a team that ...

User comments : 0