At least as intriguing as Saturn is its giant moon Titan.
"You can see Titan through a telescope--an 8th magnitude "star" a few ring-diameters from Saturn, moving from night to night as it orbits the planet," notes Adams. Titan is bigger than Mercury and Pluto, and it has an atmosphere 60 percent denser than Earth's. In other words, Titan is a full-fledged world. If it orbited the sun it would surely be considered a planet.

The curious thing about Titan is how little we know about it. It could be teeming with life or peppered by ruins from ancient civilizations, and we wouldn't know because Titan is completely covered by thick orange clouds. A camera onboard the Hubble Space Telescope has been able to see through them, to a degree, by observing at infrared wavelengths. The images hint of continents and seas, but Titan is so far away even Hubble can't take a clear picture of it.

In January 2005, the European Space Agency's Huygens probe will finally enter Titan's clouds to find out what lies underneath. This could be one of the most exciting moments in solar system exploration -- ever. Huygens will take more than 1,100 images during its two and a half hour descent by parachute. Scientific instruments will sample Titan's atmosphere, gauge its winds, and--if the probe survives landing--measure the physical properties of the ground.

Huygens probably won't find evidence of life, at least not life as we know it. Titan is too cold. Its surface temperature, researchers estimate, is minus 178 Celsius (289 Fahrenheit below zero). This doesn't mean life is impossible, though. Titan's atmosphere is rich in organic compounds: ethane, methane, hydrogen cyanide and others. The low temperature of the moon encourages ethane and methane to liquefy, so there might be puddles, lakes or even oceans of liquid hydrocarbons sloshing around on the surface. Perhaps these are places where organic molecules get together for the first stirrings of simple life.

The truth is, no one knows what Huygens will find. Or Cassini. And that's what makes exploration fun--something worth pondering this New Year's Eve. At the stroke of midnight. Looking up at a world of mystery.

Written by Dr. Tony Phillips, Science@NASA, NASA's Marshall Space Flight Center.

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