If all goes according to plan, and assuming NASA scientists didn't screw up their metric to english conversions again, the Cassini space probe will slip between two of Saturn's rings later tonight and go into orbit around the planet. It will spend the next four years there, snapping pictures, taking measurements, performing spectro analyses, conducting experiments, and desperately looking for Saddam's missing weapons of mass destruction.
In what is expected to be the mission's highlight--assuming that no ties to Al Qaeda are found--Cassini will launch the smaller Huygens probe in January. Huygens will then parachute into the atmosphere of Saturn's largest moon, Titan, and slowly descend to its surface. Scientists hope that data gathered during its descent will solve the longstanding mystery of why a satellite of Saturn would be named after an NFL football team.