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Fraser
2005-Apr-26, 05:31 PM
SUMMARY: During its recent Titan flyby, NASA's Cassini spacecraft discovered that the outer layer of the moon's thick atmosphere is filled with complex hydrocarbons. Titan is very cold, so scientists expected that these hydrocarbons would condense out of the atmosphere and rain down on the moon's surface. Instead, some process of interaction between Titan's atmosphere, sunlight, and Saturn's magnetic field are keeping them aloft and cycling them through the atmosphere.

View full article (http://www.universetoday.com/am/publish/hydrocarbons_titan_atmosphere.html)

What do you think about this story? Post your comments below.

om@umr.edu
2005-Apr-26, 06:25 PM
I am surprised that heavy hydrocarbons do not freeze out of Titan's atmosphere.

However, the high abundance of hydrocarbons in Titan's atmosphere further confirms the link of material in the outer parts of the solar system with light elements, like H, C, and N.

The article says Titan's atmosphere is composed primarily of nitrogen (as is Earth's atmosphere) followed by methane, the simplest hydrocarbon. Where is the oxygen?

Is there any estimate of water on Titan?

With kind regards,

Oliver
http://www.umr.edu/~om

John L
2005-Apr-26, 06:43 PM
I haven't seen any estimates of water ice yet for Titan. Another Cassini discover is that the Saturnian moon Enceladus has a water vapor atmosphere which can be seen here (http://www.universetoday.com/am/publish/enceladus_atmosphere.html). Of course, that is a tiny moon with weak gravity, so the water vapor atmopshere is thin, but it exists. Furthermore, there is molcular oxygen in Saturn's rings which you can read about here (http://www.saturntoday.com/news/viewpr.html?pid=16233). It was long thought that only life produced sustainable levels of molecular oxygen, but it seems there are natural reactions that can as well.

Guest
2005-Apr-26, 07:42 PM
As far as I can understand it, Titan is mostly rock and water ice in equal amounts; the nitrogen, methane and hydrocarbons are mostly present in the atmosphere and as relativly thin layers on the surface.

Oxygen can be present due to photodissociation - however the sunlight is quite dim out at Saturn's orbit.

antoniseb
2005-Apr-26, 07:48 PM
Originally posted by om@umr.edu@Apr 26 2005, 06:25 PM
I am surprised that heavy hydrocarbons do not freeze out of Titan's atmosphere.

The article suggested that these heavy organics were being formed in the extended atmosphere by UV rays interacting with Methane and anything else out there. There is a possibility that they are freezing out as fast as they are forming.

GOURDHEAD
2005-Apr-27, 02:11 PM
Is there any estimate of water on Titan? Due to the abundance of water in the MW and in this region of it in particular, I expect Titan to be mostly water by volume if not by mass.