Follow this link to skip to the main content

About Saturn & Its Moons

left blue corner of a tab Introduction right blue side of a tab left blue side of a tab Recent Discoveries right blue side of a tab left blue side of a tab News and Features right blue side of a tab left blue side of a tab Image Gallery right blue side of a tab left blue side of a tab Science Objectives right blue side of a tab left blue side of a tab Publications right blue side of a tab

Saturn - Recent Discoveries

Mimas Blues
Saturn’s blue north, as seen by Cassini in 2004.
When Cassini arrived in 2004, Saturn's northern hemisphere had a different look than when NASA's Voyager spacecraft flew by the planet in 1980. When Voyager visited, it was near the time of equinox, with ring shadows only across the equator and golden-hued clouds covering the planet. When Cassini got to Saturn, ring shadows draped across the northern hemisphere, whichappeared bluish, much like the deep, clear atmospheres of Uranus and Neptune. Scientists say that the ring shadows probably cooled the atmosphere down in the north, so golden and tan-colored clouds, visible in the Voyager images, sink to depths where they are no longer visible. (See Cassini Spacecraft Witnesses Saturn's Blues.)

Saturn has powerful lightning storms, 10,000 times stronger than on Earth, that occur in huge, deep thunderstorms columns nearly as large as the entire Earth. The storms occasionally burst through to the planet's visible cloud tops.

Saturn's auroras vary from day to day as on Earth, but rather than last a few minutes as on Earth, they can continue for days. The Sun's magnetic field and solar wind may have more to do with the aurora than previously believed. (See NASA Spacecraft Help Solve Saturn's Mysterious Auroras.)

Saturn's Polar Aurora
The enormous aurora over Saturn's north pole, seen in infrared.
Winds on Saturn have also changed since Voyager. "The clouds at the equator no longer come around at the same rate," says Dr. Andrew Ingersoll, a member of the Cassini imaging team and professor of planetary science at the California Institute of Technology in Pasadena, California. "It is possible that Saturn will lose its place as the windiest planet in the solar system."