Wednesday, June 30, 2004

Putting on the Brakes...

We're only hours away from the riskiest part of the Cassini-Huygens mission to Saturn -- braking! The Cassini probe has been slowing down naturally for quite some time as it approaches aphelion in its solar orbit. All that's required now is a successful 96-minute main engine burn to reduce its speed enough to be captured into Saturn orbit. If all goes well, we'll have a treasure trove of science beamed back from Saturn during the next four years.

In the meantime, here is more of what Cassini has treated us to so far:
Rotating view of Titan
Titan! Saturn's largest moon is seen here in an animation of its rotation. This will be the destination of the Huygens probe when it detaches from Cassini in six months -- parachuting down into the atmosphere of one of the largest moons in the solar system.

And at this site, you can listen to Saturn's rotation as recorded by Cassini. Here are the radio emissions of charged particles interacting with Saturn's magnetic field, shifted into the frequency range detectable by the human ear. Using this method, scientists have determined the average rotation period of Saturn to be about 10 hours and 45 minutes. Strangely, this is six minutes slower than the measurements of the Voyager flybys over twenty years ago. Is Saturn slowing down?