Cassini Doubleheader: Flying By Titan and Dione

Cassini Doubleheader: Flying By Titan and Dione April 2, 2010

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-110&cid=release_2010-110

In a special double flyby early next week, NASA's Cassini spacecraft will visit Saturn's
moons Titan and Dione within a period of about a day and a half, with no maneuvers in
between. A fortuitous cosmic alignment allows Cassini to attempt this doubleheader, and
the interest in swinging by Dione influenced the design of its extended mission.

The Titan flyby, planned for Monday, April 5, will take Cassini to within about 7,500
kilometers (4,700 miles) of the moon's surface. The distance is relatively long as far as
encounters go, but it works to the advantage of Cassini's imaging science subsystem.
Cassini's cameras will be able to stare at Titan's haze-shrouded surface for a longer time
and capture high-resolution pictures of the Belet and Senkyo areas, dark regions around
the equator that ripple with sand dunes.

In the early morning of Wednesday, April 7 in UTC time zones, which is around 9 p.m.
on Tuesday, April 6 in California, Cassini will make its closest approach to the medium-
sized icy moon Dione. Cassini will plunge to within about 500 kilometers (300 miles) of
Dione's surface.

This is only Cassini's second close encounter with Dione. The first flyby in October 2005,
and findings from the Voyager spacecraft in the 1990s, hinted that the moon could be
sending out a wisp of charged particles into the magnetic field around Saturn and
potentially exhaling a diffuse plume that contributes material to one of the planet's rings.
Like Enceladus, Saturn's more famous moon with a plume, Dione features bright, fresh
fractures. But if there were a plume on Dione, it would certainly be subtler and produce
less material.

Cassini plans to use its magnetometer and fields and particles instruments to see if it can
find evidence of activity at Dione. Thermal mapping by the composite infrared
spectrometer will also help in that search. In addition, the visual and infrared mapping
spectrometer will examine dark material found on Dione. Scientists would like to
understand the source of this dark material.

Cassini has made three previous double flybys and another two are planned in the years
ahead. The mission is nearing the end of its first extension, known as the Equinox
mission. It will begin its second mission extension, known as the Solstice Mission, in
October 2010.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space
Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the
California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for
NASA's Science Mission Directorate in Washington. The Cassini orbiter was designed,
developed and assembled at JPL.

More information about the Titan flyby, dubbed "T67," is available at:
http://saturn.jpl.nasa.gov/mission/flybys/titan20100405/ .

More information about the Dione flyby, dubbed "D2," is available at:
http://saturn.jpl.nasa.gov/mission/flybys/dione20100407/

#2010-110

-end-

Jia-Rui Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jia-rui.c.cook@jpl.nasa.gov

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=ehKOIYODLmIWKdJ&s=kuJ2L7NNKgIOJ6MTIuE&m=rlI1LgOVIfK5E

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=hkIUJ7PPKpL3InI&s=kuJ2L7NNKgIOJ6MTIuE&m=rlI1LgOVIfK5E