[X] My Assistant

[SFJCody]

Is a Discovery class Titan lander/aerobot remotely conceivable?

It would be nice to see Cassini's relay capability get a second workout...

[edstrick]

As I recall from press release stuff last year, Huygens saw little or no Argon36 and no Krypton and Xenon, despite a special concentrator for inert gasses that was to remove nitrogen and other reactive gasses from a sample for analysis during descent.

This means that Titan has *no* remnant of a primordial atmosphere of gasses trapped form the circum-saturn nebula.

This means that Titan either has *no* remnant of a primary outgassed atmosphere (formed immediately after accretion) that contained Argon, Krypton and Xenon that was physically trapped in the rocks and ices that form Titan, or that those gasses were never released from the interior <not likely, see below>.

This means that essentially 100% of the Argon 40 seen in Titan's atmosphere was outgassed progressively over it's history as a decay product of Potassium 40, and essentially zero % of the Argon 40 is primordial.

Thus, since the decay rate of K40 is known, and the total amount of K40 in Titan is approximately known (solar abundance in the rock component of Titan), we know that Titan has outgassed it's accumulated Ar40 with at least enough efficiency to put the observed amount in the atmosphere. This is ***NOT*** a trivial observation. The only things we don't know is (1) when the outgassing happened: efficiently and early, or more inefficently and later (when there was more Argon 40 produced) and (2) whether Titan has lost large amounts of Ar40 from it's atmosphere to space and has thus outgassed more than the observed amount.