Possible Cryovolcano Discovered on Titan 116
Rei writes "NASA's Jet Propulsion Laboratory is reporting that the Cassini spacecraft has observed what appears to be a cryovolcano on Saturn's moon Titan. Given the absense of a global methane sea on Titan, the snail-shaped structure with what appears to be a caldera on top could explain how Titan's methane stays replenished. It could further explain the dry drainage channels discovered by the Huygens lander as being formed by heavy methane rainfall after eruptions."
Guess what... (Score:4, Informative)
astronomy dominee [wikipedia.org]
Re:Titan Climatology (Score:5, Informative)
Although they are made out of "solid" matter the flows seem almost liquid in nature. Don't think of the methane as one huge frozen lump, but rather many solid lumps in motion.
Re:Titan Climatology (Score:5, Informative)
Definition of Cryovolcano (Score:5, Informative)
This term was coined by NASA in late 2004, when the Cassini space probe observed cryvolcanoes and cryogenic lakes for the first time."
definition quoted from explore-dictionary.com [explore-dictionary.com]
Take a look for yourself (Score:5, Informative)
Today's Astronomy Picture of the Day [nasa.gov] show a nice picture of this.
If you're interested in this stuff, bookmark http://antwrp.gsfc.nasa.gov/apod/astropix.html [nasa.gov], which just points to the current picture of the day.
Re:Titan Climatology (Score:3, Informative)
I haven't seen the numbers crunched that would tell how much energy Titan could derive from it's orbital eccentricity, but it wouldn't take much to drive methane ice at cryogenic temperatures.
Cryoclastic eruptions? (Score:5, Informative)
Titan is the only moon in the solar system to have a substantial atmosphere
Triton, Neptune's large moon also has a substantial Nitrogen atmosphere, enough to entrain geyser plumes [nasa.gov] that move downwind. Ganymede has a thin atmosphere as well.
the hypothesis is that this feature is probably formed by plumes of frozen methane, forced from underground, which then slowly evaporate into methane gas.
It will be interesting to see what style of volcanism dominates on Titan - "cryoclastic" eruptions of methane gas and ammonia-hydrate ice crystals, or gooey water/hydrocarbon flows. The light colored lobate features surrounding the caldera in the TIMS image suggests the later. The apparent ring faults surrounding the caldera also suggest that this is a shield profile volcano built by effusive eruptions. It will be interesting to measure its profile with Cassini's radar to find out for sure.
Re:What a nerd. (Score:2, Informative)
A volcano-like feature on a planet or moon, that may or may not be an actual volcano. Examples have been found, for example, on the surface of Ganymede.
http://www.google.com/search?hl=en&q=cryptovolcan
Re:Cryoclastic eruptions? (Score:3, Informative)
What about Iapetus? It has what looks like wind blown streaks, but it doesn't appear to have an atmosphere.
Iapetus, Dione, Rhea all have bright wispy terrains that may have an impact or tectonic origin. There is no evidence at all that these features were disbursed by an atmosphere. But Triton's dark geyser plumes have been observed actively rising and disbursing downwind at altitude.
Re:no ocean? (Score:2, Informative)
The Hyugens probe appearently landing on one of those "lakes". They speculate that it is a dried-out lake-bed. Appearently it fills up when the vocanos errupt.