Titanic Titans...

Orion1

Mission to Saturn:
International effort to explore Saturn, Titan

NASA, the European Space Agancy and Italy's space agancy teamed up to produce the Cassini-Huygens mission to explore Saturn and its largest moon, Titan. The US$3 billion project, which launched Oct. 15, 1997, should enter Saturn's orbit July 1. Cassini will spend four years orbiting the gaseous giant to learn more about the planet's rings, which as made up of ice and rocks. Clues gathered during the robotic Saturn mission could shed light on the origins of the solar system, NASA built the Cassini craft, which is carrying the ESA-built Huygens probe.

Titans probe:

Titan, the largest of Saturn's 18 moons, is an important mission target. On Dec. 25, Cassini will release the Huygens probe. By Jan. 14, the probe should hit the moon's atmosphere at 13,400 mph. During its three-hour parachute journey to the surface, it will measure wind speed, analyze the atmosphere and take photographs. Titan's atmosphere is believed to be similar to a primordial Terra.

Reference:
http://www.nasa.gov

Phobos

Well, since you brought it up...
http://www.physicspost.com/science-article-196.html

Orion1

The latest images of Titan revealed a single set of clouds about the size of Arizona and dark and light shapes across the moon that the imaging team is analyzing.

The shots of the moon's surface features were taken during Cassini's first pass Friday at a distance of about 200,000 miles.

Scientists believe the moon could have chemical compounds much like those that existed on Earth billions of years ago before life appeared.

Big enough to be a planet in its own right, Titan has an atmosphere 1 1/2 times as dense as Earth's, containing organic -- meaning carbon-based -- compounds. Scientists believe there could be hydrocarbon seas or lakes.

Turtle said initial data analysis suggested the moon is the site of geologic activity that could include wind and erosion and development of the lakes or rivers.
The spacecraft will make 45 more fly-bys of the moon -- coming with 600 miles of Titan at times -- and then send a probe into its atmosphere in January. The probe, named Huygens, will send pictures back to Cassini as it makes a 2 1/2-hour descent by parachute through the atmosphere.

What is the density of Saturn's moon Titan?
[tex]M_t = 1.3*10^{23} kg[/tex] - Titan's Mass
[tex]r_t = 2.575*10^{6} m[/tex] - Titan's Radius

[tex] \rho_t = \frac{3 M_t}{ 4 \pi r_t^3}[/tex]

[tex] \rho_t = 1817.703 kg*m^{-3}[/tex]

Reference:
http://166.70.44.66/2004/jul/0704200...n_w/181000.asp

Janitor

One of those links says, "... they were puzzled that the Cassini spacecraft hadn't glimpsed any evidence of liquids... One indistinct circular shape could be a huge crater, and a linear shape could be a hydrocarbon river or a fault line..."

I too am mildly disappointed that there is not (yet) clear evidence of substantial-sized lakes.

Phobos

Astronomers have found 31 moons around Saturn (many are very small). They'll probably find more with the ongoing Cassini mission.