Titanic Saturn

barakn writes "Using the Crab Nebula as an x-ray source, scientists have observed Titan's x-ray shadow to get a preliminary estimate of the extent of its outer atmosphere. On the same page, another article discusses the possibility that the hydrocarbon seas of Titan bear waves, albeit slow-moving and widely spaced, 7 times higher than waves on Earth (additional wave links here, here, and here). And Cassini-Huygens has snapped a photo of Saturn showing "two small, faint dark spots" in the southern hemisphere (this link has convenient arrows pointing at them, or here). Cassini-Huygens will achieve Saturn orbit insertion on July 1st. Huygens will detach and enter Titan's atmosphere in January, 2005."

Comments

Re:Life imitates art?

[Anonymous Coward]

Fuck that, read Baxter's 'Titan' if you really want a hard sf view of the place. Depressing, too.

Re:color me ignorant, but...

[Anonymous Coward]

Do all the hydrocarbons on Titan make it a good spot for mining/drilling?

Not really. The energy it would take to bring a pound of hydrocarbons back to Earth from Titan is likely much more than you'd get from burning it.
(30 km/sec is equivalent to 450 MJ/kg; burning gives about 10 MJ/kg).

Re:A thick atmosphere in low gravity?

[CheshireCatCO]

I don't know who told you that, but that's totally wrong. There's no way a significant fraction of the atmosphere would ever be re-accreted by the planet from a torus, first of all. (Io has a very distinct torus and its atmosphere is all by non-existant.)

Second of all, we have yet to observe any Titan-torus, last I heard. (About two weeks ago, a comment made from one of the Cassini principle investigators.) If there's so much gas there, why can't we see it?

Finally, the reason Titan can hold a thick atmosphere is, as some already stated, because it's so bloody cold. You can do the simple atmospheric calculations and show that at the tempertures of Titan, it can hold that atmosphere pretty nicely.

A good place to look for details is _The New Solar System_, Beatty, Petersen, and Chaikin, editors.

Re:Why are major "storms" in souther hemisphere?

[barakn]

Saturn's southern hemisphere is currently receiving more sunlight (i.e. summer), so one might expect solar heating to cause turbulent convection in the southern hemisphere. Half a Saturn-year from now (15 Earth years), there may very well be storms in the northern hemisphere. El Nino is a bit of a red herring. There's only been one recorded hurricane in the southern Atlantic (this week), and hundreds in the northern Atlantic. The distribution of land masses is asymmetric, so we should expect this.

Jupiter, on the other hand, has an obliquity of only 3.08 degrees, so there should be little or no seasonal effect. The Great Red Spot is truly mysterious.

Copying an old experiment

[techno-vampire]

Back in the 80's, JPL changed the course of Voyager I to go behind Titan. The distance at which the signal started to drop, and the rate it dropped at gave us very good measurements of the atmosphere's depth and density. In fact, if the probe's distance from the center of Titan had been cut in half, it would have crashed. That's right, it was less than two radii out! I know, because I worked with the man who wrote the navagation system they used back then (The late Daniel J. Alderson.) and stll know, slightly, the man who used it for this, Bob Ceserone.

Re:A thick atmosphere in low gravity?

[lab16]

Actually, IIRC, most astronomers now believe that the reason that mars doesn't have an atmosphere is because of a reverse runaway greenhouse effect.

Mars is just far enough away from the sun that the CO2 from its atmosphere started to condense into the rocks and water (which was present at the time this was happening), this caused the temperature to lower, causing more CO2 to go away, lowering the temp and so on.
This also explains why Venus has a thick hot atmosphere.
You can find more if you google for it.