A World Unveiled: Cassini at Titan

From Voyager, Titan was so unusual. All we could see from Voyager is this hazy world. We couldn't see through to the surface. And that's why we had to go back with Cassini carrying the Huygens probe to try to see what does the surface of Titan look like.

So the Huygens probe parachuted through in 2005. And we landed on the surface. And we saw an amazing world. It was incredible how Earthlike Titan appeared.

It had river channels. It had lakes. It had sand dunes. The only difference is, it's very cold on Titan. And the liquid that flows through Titan's rivers is methane instead of water.

The Cassini-Huygens mission has been one of the greatest voyages of discovery in the history of science. We have learned and discovered more things about a previously unknown dynamic system--a system that's a billion miles from us: the Saturn system--than we ever could have imagined.

One of the pinnacles of that has been the discoveries on Titan. Titan has turned out to be a very complex world. It has geology. It has methane rain. It has lakes and seas. It has dunes of organic molecules. And it has a lot more secrets that it's still hiding from us. I think that really what makes people so excited about Titan is this combination of familiarity and alienness.

We had 126 close flybys with a spacecraft with, you know, a dozen instruments that in each of those flybys are all taking data about different aspects of Titan. Not only was Titan fascinating in its own right: a moon the size of the planet Mercury, it was also Cassini's gas tank. It allowed us to change the shape and orientation of the orbit to explore the poles of Saturn, the rings, and all of the icy moons by carrying a lot less fuel than it would have to have carried otherwise. It gave us the energy to go all the way across the rings and fly between the gap between the rings and the planet.

Because of these flybys of Titan using Titan as a gravitational slingshot. And so many of the other remarkable discoveries that have been made by Cassini--for example, mapping the composition of the plume of Enceladus, would not have been possible without Titan there. We could not have gotten to these places without using Titan. And so I think Titan has really been a particularly special place to explore just because of all the complexity in the system and the puzzles that it has given us.

California Institute of Technology