July 10, 2012

Cassini Flying High In Saturn’s Rings Again

Lee Rannals for - Your Universe Online

NASA's Cassini spacecraft is flying high amongst the rings of Saturn for the first time in nearly two years.

The spacecraft is pumping out views of Saturn's spectacular rings because it has changed the angle at which it orbits the planet, regularly passing above and below Saturn's equatorial plane.

In order to change its angle, Cassini had to use the gravity of Titan to change its trajectory. Titan revolves around Saturn within a plane very close to Saturn's equatorial plane. As the spacecraft flies past Titan, the moon's gravity bends Cassini's path by pulling it towards Titan's center.

"Gravity assists are key to Cassini´s ever-changing orbital geometries," Cassini's lead navigator, Duane Roth, said in a blog post. "Onboard propellant alone would quickly become depleted attempting to accomplish these same changes."

These steeply inclined orbits around Saturn help scientists to get a better view of the poles and atmosphere of it and its moons.

Cassini's return to the rings has already started to pay off for scientists, as one group has restarted the imaging team's studies of the famous propeller features.

These features are small, longitudinally limited orbiting gaps in the rings that are cleared out by objects smaller than known moons, but larger than typical ring particles.

Matt Tiscareno, a Cassini imaging team associate at Cornell University, and colleagues had been following these objects for several years, but haven't seen them in the last two because of the position of the spacecraft.

NASA said scientists are eagerly awaiting images of the polar regions of the planet, and its moons.

“We´re entering a new episode in Cassini´s exploratory voyage through the Saturn system,” Carolyn Porco, imaging team lead, based at the Space Science Institute, Boulder, Colorado, said in a press release. “These new ring results are an early harbinger of great things to come. So watch this space!”