Iapetus is a curious beast as moons go, with one side covered in bright snow-like material, and the other in a dark layer that isn't yet well understood. Scientists hope that this week's flyby, at an altitude of 1020 miles, and a speed of just 1.5 miles per hour, will help them understand better understand these formations.

The 892-mile-wide moon also has a unique belt of mountains running around its equator, seen on no other moon in the solar system, with peaks reaching up to 12 miles high, or a little more than twice the height of Mt. Everest.

Cassini Scientists aren't clear what caused this formation. Some believe it folded upwards with shifts in the moon's crust, while others think that a long crack in the crust allowed material from the interior to erupt consistently around the equatorial belt, forming the mountains.

The data sent back by yesterday's flyby will hopefully provide clues to all these mysteries. As NASA analyzes and processes the raw pictures, more will be available online (and here).

UPDATE: The seriously close-up pics have begun filtering online. The third picture now included in this post was taken at a distance of about 818 miles. There are many more where that came from.

Source - Wired

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