[X] My Assistant

[Guest_AlexBlackwell_*]

An interesting (and topical) paper in press with the journal Planetary and Space Science:

Titan's methane cycle
Planet. Space Sci., In Press, Corrected Proof, Available online 25 July 2006
Sushil K. Atreya et al.
Abstract
Preprint (451 Kb PDF)

[volcanopele]

There is a nice illustation of methane rain on the Astronomy Picture of the Day site:

http://antwrp.gsfc.nasa.gov/apod/ap060802.html

I would lose the lightning and maybe lose the hills. The area with the lakes actually appear quite flat. I would also wouldn't call the researchers on those rain studies "astrobiologists", astrometeorologists maybe...

[Thorsten]

There is a nice illustation of methane rain on the Astronomy Picture of the Day site:

http://antwrp.gsfc.nasa.gov/apod/ap060802.html

I would lose the lightning and maybe lose the hills. The area with the lakes actually appear quite flat.

Sure, there are too many hills and too much lightning, compared to real Titan – and the rain clouds would probably be much, much higher in the sky (stratiform methane clouds form 21 – 30 km above the ground) but I really liked the illustration by Mark Garlick. Especially the darkness that one would experience on Titan in the middle of a methane storm and the fierceness of this “methane monsoon” is nicely accentuated. However, since raindrops would fall at a snowflake-like pace through the thick atmosphere of this low gravity moon, it would probably be some kind of “slow-motion rainstorm”.

I have read somewhere that our knowledge on Titan at the beginning of this century was in many aspects comparable with our knowledge on Mars and Venus back in the ‘50es. Think of all the great Pre-Cassini illustrations - such as this one or the ones from Don Dixon:

http://www.cosmographica.com/gallery/portf...0-TitanLake.htm

- on Titan’s lakes. Now compare them with Pre-Mariner illustrations of Mars, showing rivers, emanating from water-ice pole caps:

http://www.astrosurf.com/lombry/Images/mars-bonestell1.jpg

or plains seasonally covered with primitive vegetation or of Venus, portrayed as misty, tropical paradise. I think the Titan illustrators didn’t do such a bad job. (Or Titan did a fairly good job in - at least partly - providing what we originally intended to find).

Edit: Couldn’t help posting this great illustration – again from the unforgettable, unrivaled Chesley Bonestell (1888 – 1986). Note the dust devils und barchan dunes to the left and the Martian vegetation to the right.

Attached thumbnail(s)