Something else on February 24 2009: Titan, Mimas, Dione and Enceladus to pass in front of Saturn

Titan compared to the Earth. On the 24th of February this moon along with three others will pass in front of Saturn.

(Here's the other thing I wrote about that's going to happen on the 24th)

On February 24 there's going to be a transit in front of Saturn of the four major moons Titan, Mimas, Dione and Enceladus, which is an event that only happens every 14 or 15 years, and is quite easy for amateur astronomers to observe as well:

"On Feb. 24th, there's going to be a quadruple transit of Saturn's moons," says Keith Noll of the Hubble Space Telescope Science Institute. "Titan, Mimas, Dione and Enceladus will pass directly in front of Saturn and we'll see their silhouettes crossing Saturn's cloudtops—all four at the same time."

Hubble won't be the only one looking. Amateur astronomers will be able to see it, too. The timing favors observers along the Pacific coast of North America, Alaska, Hawaii, Australia and east Asia.

Titan's transit is the most interesting because of the volume of hard science it's able to reveal:

"The transit of Titan will be of particular interest," says Noll. "Researchers plan to use Saturn as a backlight to probe the size and transparency of the giant moon's atmosphere." Hubble will also capture a rare view of the rings almost edge-on, a point of view that can reveal ring-warps, undiscovered satellites, and new information about the reflectivity of ring particles.

For more information on why transits like this are so valuable for bodies with atmospheres, see the Transit of Venus page on Wikipedia; it's the same concept.