NEWS | September 5, 2017

Nine Ways Cassini Matters: No. 3

With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. > Full image and caption

Cassini is, in a sense, a time machine. It has given us a portal to see the physical processes that likely shaped the development of our solar system, as well as planetary systems around other stars.

Cassini has provided a brief glimpse into deep time in the Saturn system. The rings, for example, are a natural laboratory for processes that form planets—a mini solar system, if you will. They show us how objects clump together and break apart. And in the ripples we can read the history of impacts into the rings. We also see “propeller” features that obey the same physical processes that form planets.

NASA's Cassini spacecraft captured these remarkable views of a propeller feature in Saturn's A ring on Feb. 21, 2017.

Moons in the Saturn system are also time capsules preserving histories of bombardment and other forces at play over time. At Titan, in particular, we have access to the kinds of complex carbon chemistry that might have taken place on Earth in its “prebiotic” days. During the Cassini mission’s finale, data about the planet’s interior and the mass of the rings will provide a powerful insights about their formation and evolution.