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Sunday, September 30th, 2012

Time Event
11:03p
Saturn's Coolest #6: Iapetus
I originally considered making a list of the top six moons of Saturn, not the top ten, because the ones up till now - as interesting as they (hopefully) have been, are just not in the same class as what's coming. Iapetus is, to me, where things really start getting good.

When Cassini (the astronomer) discovered Iapetus, he had a problem: he could only see it on one side of Saturn and not the other; years later, he saw it on the other side, but he needed a bigger telescope: it was only one tenth as bright.

Why? Well, obviously it was bright on one side and dim on the other... but we had to wait till Cassini (the orbiter) got to Saturn before we had any decent pictures that explained any further. (Arthur C. Clarke made this differential an important plot point of his novel 2001. Clarke may have been closer to the truth than he knew... but I'll get to that.) Read more...Collapse )

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