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In this week's Economist, The Dark Side of the Moon:

IN THE science-fiction classic “2001”, a spacecraft is dispatched to examine Iapetus, Saturn's third-largest moon, because of an anomalous signal sent from Earth's moon to Iapetus. In the book, as in reality, there is something else odd about Iapetus: unlike any other object in the solar system, one-half of its surface is ten times darker than the other. Arthur Clarke speculated that it was a signal from an alien civilisation. Astronomers naturally tend to doubt that explanation but have had difficulty coming up with a better one.

[...]

It turns out that the two sides look rather similar to the radar, and about the same amount of signal bounced off either side. This [...] means that whatever the dark material is, it is either electrically non-absorbing, or placed in a very thin layer, only a few centimetres thick. Though astronomers are fairly certain that Iapetus is mostly made of water, they are unsure of what else is there. The radar results point towards ammonia as a likely component, because it absorbs radar signals. But it may lie just below the surface.

The radar data still leave much to be explained. But Cassini, an unmanned American spaceprobe, is due to arrive at Saturn on July 1st. Its four-year mission is planned to include a close approach to Iapetus. So even if the scheduled date of 2001 has now passed, a definite answer should come soon.

Interesting. But let's not mention that HAL 9000 is still fiction. And that we don't have a base on the moon. And that the space station we do have in orbit around the Earth is a glorified shoebox, instead of the magnificent ring in 2001. And...

Okay, I'll stop complaining.

On a lighter note, this reminds me that I've been thinking of re-reading Rendezvous with Rama (of which a movie has also been long-rumored, btw). That book and Rama II are among my SF favorites of all time.

Categories: science
Posted by diego on April 23 2004 at 12:19 PM