Carolyn Porco

As a planetary system, Saturn holds the greatest promise for answering questions that have a far broader scientific reach than Saturn itself.

It would be impossible in a few words to describe all that we've found with Cassini. No mission has ever gone as deep for as long on a planetary system as rich as Saturn's.

The Cassini mission was all about a comprehensive investigation of Saturn and everything in the Saturn system, and it's been a mission that's been done jointly with the Europeans.

Most of the solar system resides beyond the orbits of the asteroids. There is more to learn there about general planetary processes than on Mars.

When the Voyager 2 spacecraft sped through the Saturnian system more than a quarter of a century ago, it came within 90,000 kilometers of the moon Enceladus. Over the course of a few hours, its cameras returned a handful of images that confounded planetary scientists for years.

No matter how you measure it, whether you measure the amount of mass or you measure the number of bodies, most of our solar system exists out beyond the orbits of the asteroids. So we could not have claimed to know our own solar system until Voyager had toured the giant planets.

The geysering on Enceladus is the most astonishing phenomenon we have in our solar system.

The reasons why images are so primal and people immediately relate to it is that we are exquisitely engineered to interpret information that is arrayed in two dimensions. That's our eyesight. That's how our eye-brain system works. So it immediately feels to us when we look at an image like we have extended our senses.

Titan is Saturn's largest moon, and, until Cassini had arrived, there was the largest single expanse of unexplored terrain that we had remaining in our solar system.

Whenever we humans think that we might be approaching something that is vaguely similar to Earth, we get very excited about it. The prospect of something familiar but yet so distant and so strange is a very exciting combination.

Voyager found Saturn to be a planet with a complex interior, atmosphere, and magnetosphere. In its rings - a vast, gleaming disk of icy rubble - the mission recorded signs of the same physical mechanisms that were key in configuring the early solar system and similar disks of material around other stars.