Cassini to explore uncharted territory beneath Saturn’s rings on probe’s final mission
The long-serving Cassini probe will be sent into the region between Saturn’s atmosphere and its rings, in order to determine how they were formed.
Afterwards, it will complete its mission by plunging safely into the gas giant. This is to prevent biological contamination of Saturn’s moons, several of which could potentially contain life.
Cassini is the first spacecraft to enter orbit around Saturn. Its lander, Huygens, detached from the spacecraft in 2004 to collect data from the surface of Saturn’s largest moon, Titan. This was the first-ever landing in the outer solar system.
During its mission, Cassini has measured Saturn’s rotational period, tested Einstein’s theory of general relativity, discovered new moons and recorded the aftermath of a ‘Great White Spot’ storm. It has completed fly-bys of Titan, Phoebe, Enceladus, Iapetus, Rhea, Hyperion and Dione.
Thanks to its observations of Enceladus, NASA scientists were able to discover a thin atmosphere, enormous water ice geysers and evidence of an underground saltwater ocean hidden beneath the moon’s entire surface.
In order to reach the unexplored region beneath Saturn’s rings, Cassini will use Titan’s gravity to slingshot itself into a new orbit that passes inside the gap between Saturn’s atmosphere and its rings. NASA scientists hope Cassini will be able to complete 22 orbits into the rings, during which it will collect data to help determine their age and composition.
Researchers hope to discover whether these rings – mostly composed of ice – are as old as the planet itself or whether they may have formed more recently. It has been suggested they could have been formed from a moon, shredded by tidal forces as its orbit decayed. Cassini will also observe Saturn’s atmosphere and take measurements to calculate the size of the gas giant’s rocky core.
During the final part of its mission, Cassini will be travelling at 70,000mph.
“At those speeds, even a tiny particle can do damage,” said NASA flight engineer Joan Stupik during a news conference in Pasadena, CA.
According to NASA project scientist Linda Spiler, “the grand finale will be spectacular”.
“We’re flying in a region that has never been explored before,” she said. “I wouldn’t be a bit surprised if some of the discoveries we make with Cassini during the grand finale are the best of the mission.”