Titan: Another special neighbor

This week’s mapping by Cassini of mountains on Titan brings back into focus another intriguing member of our solar system.

Cassini has found what is believed to be the highest mountain on Titan, a 10,948 peak near the equator.

Titan is bigger than Mercury and smaller than Mars. It is not a hospitable place. The surface temperature is about minus 280 degrees Fahrenheit and the air pressure is approximately 22 pounds per square inch compared with roughly 15 psi on earth. Titan’s gravity is slightly less than that of the Moon.

Yet NASA has described Titan as “ . . . one of the most Earth like worlds we have found to date.” The reasons lie in the unique combination of Titan’s composition, its distance from the Sun and its place in the orbit of Saturn.
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NASA hoping for a stellar look at the plumes of Enceladus

This week it was possible to observe the light of a star in the Orion constellation though the plumes of
Enceladus and NASA positioned Cassini to do that.

The star is Epsilon Orionis, the middle star in the belt of Orion. Such an alignment is called a stellar occultation. Usually “occultation” refers to an event where one object blocks and observer’s view of a second object.

In this case, the observer’s view isn’t blocked, its filtered through the water and gas of Enceladus’ plumes. Cassini has made four stellar and one solar occultations of the plumes over the last ten years.

From a distance of 535,000 miles from Enceladus NASA will use Cassini’s Ultraviolet Image Spectrograph (UVIS) to record the filtered starlight. The star itself is 2,000 light years from Enceladus.
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