Updated Titan Map Options

[alan]

I'm looking for a recent map ot Titan. Steve Albers's page links to one done by Fridger Schrempp in April 2005. Cassini has done a dozen flybys since then. Does anyone know if an updated map has been released.

[Julius]

Has someone got an explanation why Titans dark flat plains are along the equator??Dont think that is coincidental!

[JRehling]

Has someone got an explanation why Titans dark flat plains are along the equator??Dont think that is coincidental!

Notice that Venus's rifts run primarily along the equator and that the Valles Marineris is roughly equatorial on Mars. With the exception of Ganymede and Callisto (which is surfacewise totally dead), all of the solid worlds in that size range have signs of equatorial tectonism.

There's a compelling overlap to be made between Venus, Mars, and Titan. Xanadu = Tharsis? Hotei = Aphrodite? The similarities are intriguing.

[dvandorn]

Notice that Venus's rifts run primarily along the equator and that the Valles Marineris is roughly equatorial on Mars. With the exception of Ganymede and Callisto (which is surfacewise totally dead), all of the solid worlds in that size range have signs of equatorial tectonism.

Hmmm... not *all* of the worlds in that range, since Venus and Earth are of near-identical size and mass. Earth has a lot of tectonic activity, but its shattered crust seems to exert more control over the orientation of rifts and crustal cracking than whatever it is on these other worlds that causes equatorial tectonics.

-the other Doug

[JRehling]

Hmmm... not *all* of the worlds in that range, since Venus and Earth are of near-identical size and mass. Earth has a lot of tectonic activity, but its shattered crust seems to exert more control over the orientation of rifts and crustal cracking than whatever it is on these other worlds that causes equatorial tectonics.

-the other Doug

Yeah, but Earth is *slightly* out of the Titan-to-Venus size range...

To address Juramike's post, it's unclear why Venus and Earth have evolved so differently, but one suggestion is that Earth's ocean is a critical difference, because metamorphic rock formed when lava meets water is inherently lighter and softer than that formed when lava erupts onto a solid surface. As small as the ocean is compared to the bulk of the mantle below it, that may change everything, creating soft, light continental plates that form on top of the heavier slabs of ocean crust.

It's clear that Earth tends to dispose of its inner heat via horizontal movement of its crust while on Venus convection is more vertical. Earth lets a little heat out all the time whereas Venus seems to have rare global meltdowns when the crustal lid gets too much heat built up underneath it. The ocean difference is a plausible explanation.

Because Earth's heat dissipation involves the horizontal displacement of crust, "aboriginal" patterns have been obliterating by the wandering of plates, whereas on Mars, Ganymede, and possibly Titan, some of the ancient crustal landmasses are still there relatively intact with some considerable tectonism having reworked large portions of the surface.

Venus's case is different: The surface there is "ancient", but only about 700 million years old, showing the scars formed since then. The oldest surfaces of Mars and Ganymede are very roughly 3.5 and 4 billion years old, respectively. As for Titan, that's not clear, but there is more than just geology going on there, so on the small scale, we can't expect anything ancient. However, the large scale features (Xanadu, Tsegihi, etc.) may be quite old, and my bet is that they are, simply because Titan's large-scale features look more like Mars's than Earth's.