Spacecraft Cassini will fly by Saturn's geyser moon, Enceladus, twice in October, the U.S. space agency NASA reported Monday.
The Oct. 9 flyby is an inside pitch -- the closest flyby yet of any moon of Saturn, at only 25 km from the surface. The Oct. 31 flyby is farther out, at 196 km.
The Enceladus geysers were discovered by Cassini in 2005. It produces a few hundred kg per second of gas and dust, which are mainly water vapor and water ice.
Since then, scientists have been intrigued about what powers them, because the moon is so tiny, at only 500 km in diameter.
Scientists are intrigued by the possibility that liquid water, perhaps even an ocean, may exist beneath the surface of Enceladus. Trace amounts of organics have also been detected, raising tantalizing possibilities about the moon's habitability.
During Cassini's Oct. 9 flyby, the spacecraft's fields and particles instruments will venture deeper into the plume than ever before, directly sampling the particles and gases.
"One of the overarching scientific puzzles we are trying to understand is what happens to the gas and dust released from Enceladus, including how some of the gas is transformed to ionized plasma and is disseminated throughout the magnetosphere," said Tamas Gambosi, Cassini scientist at University of Michigan.
On Oct. 31, cameras and other optical remote sensing instruments will be front and center, imaging the fractures that slash across the moon's south polar region like stripes on a tiger.
These two flybys might augment findings from the most recent Enceladus flyby on Aug. 11, 2008, which hint at possible changes associated with the icy moon.
Results from Cassini's magnetometer instrument during the August flyby suggest a difference in the intensity of the plume compared to earlier encounters. Information from the next two flybys will help scientists understand these observations.
Cassini has been orbiting Saturn since 2004. Four more Enceladus flybys are planned in the next two years, according to NASA's mission schedule.
|
About Us 
