AstroTalk Episode November 24, 2016
Cassini in Orbit Around Saturn's Rings and Mars Ice Deposits
3:03pm - 3:29pm
Scientists have determined that the Utopia Planatia region on Mars holds as much water as Lake Superior, the largest of the Great Lakes. The deposits are under a layer of soil, in the form of frozen matter. If the water ice mixture were exposed to the Martian atmosphere, then it would sublime into the atmosphere and be lost. The deposit is thought to be away from the poles, and the tilt of Mars, which varies in cycles of 120,000 years has an effect on the water ice mixture. When the poles are heated during this cycle, then this drives the water-ice towards the equator.
The Cassini mission on Saturn is heading for another experiment. In this one, beginning on November 30, the spacecraft will make orbits, at a high tilt to the plane of the rings, in an effort to orbit, and then come close to, the rings of Saturn. The A, B & F rings will be studied in these orbits. The spacecraft will come close enough to the rings so as to be able to sample gas and some small particles from the rings. If the particles are too big, though, they could easily damage the spacecraft, rendering it useless. The A ring is one main target, as scientists want to study the propellers in the A rings. Propellers are the signatures of unknown moonlets. Many of Saturn's smallest moons are thought to originate, and form, inside the rings. The tiny moonlets Pan, Atlas, Pandora and Daphnis are presently orbiting close to the A ring. Because of this, these small moonlets will also be studied, in effort to reveal more of their secrets. The Cassini spacecraft is running low on fuel, so in April 2017, the spacecraft will make a final, daring dive into history, burning up in Saturn's atmosphere. Thank you for all the beautiful pictures, and memories, Cassini.