Probe Reveals Storms and Ocean
Cassini’s discoveries have changed astronomers’ view of the gas planet in the outer Solar System and made Saturn’s moons the main focus of the search for life in space.
Magnetic Field Makes Supersize Aurorae
Saturn has a strong magnetic field, and as solar wind strikes it, particles build up at the poles, where the field is weaker. These charged particles make hydrogen in the atmosphere glow.
Cassini showed the field is distorted, where it meets Enceladus’ south pole, as water particles from the moon’s geysers bend along field lines. This discovery gave astronomers a clue about the existence of an ocean under Enceladus' ice sheet.
Monster Storm Rages Annually
Every Saturnian year, high winds leave clear evidence in Saturn’s northern hemisphere. The most recent of the huge storms started 10 years early. So Cassini took photos and measured the weather system, which stretched 300,000 km and had wind gusts of 500+ km/h. In 2013, the probe’s revealed that white storm "stains" include water ice and frozen ammonia, which reach 150 km into space from the planet’s surface.
Rings Have Very High Fringes
Cassini has used radio to observe that Saturn’s rings are indeed made of billions of ice chunks ranging from less than a sand grain to kilometres across.
Cassini also discovered that the rings have fringes. The vertical strings along the B ring can reach 3000m high, while the A and C ring fringes are 10 m high. These vertical formations probably form when Saturn’s small moons stir up the material, as they speed by.