Tuesday, November 16, 2004
The dark side of the moon
Go here: http://saturn.jpl.nasa.gov/cgi-bin/gs2.cgi?path=../multimedia/images/large-moons/images/PIA06521.jpg&type=image for the latest Cassini image of Iapetus, moon of Saturn. Observant amateur astronomers can see the difference in the moon observing from earth. The brightness differs by about two orders of magnitude, if I remember correctly. That's a little more than the difference between the brightest and dimmest stars in the Big Dipper.
John Varley, in his sf novel Titan, described a vast living organism that was responsible for the black hemisphere of Iapetus, and that in the 2010's, it had mysteriously cleared up. The human expedition to Saturn investigates, but gets caught up in a whole other story, finding themselves at the mercy of one of the moon-sized beings responsible for various antics in the outer solar system. A good read, but no longer scientifically accurate.
Many great sf stories have been rendered scientifically obsolete by new discoveries these past few decades. But I'm curious to see what Cassini really finds on Iapetus. I think a close look is planned in a few years after the probe gets a few dozen Saturnian orbits with the planned flybys of Titan under its belt. The Cassini web site has tons of fascinating information, including scads of images. While you're in the neighborhood there, check out the home site for the Jet Propulsion Laboratory (JPL) too. I like to keep up with the Mars rovers and results from the Spitzer telescope. What great times for a space buff to live in!
