Upcoming Cassini Flybys

[Christopher K.]

E-9
On Wednesday (28 April) the Cassini spacecraft will fly by Saturn's moon Enceladus. The craft will be passing 100 kilometers above the surface at 6.5 kilometers per second--15,000 mph.

Cassini will attempt to determine the nature of a so-called "hot spot" discovered at Enceladus' south pole. This will be attempted using the largest instrument in the mission--the Radio Science Subsystem. One section is on Cassini itself and the rest of the components reside on Earth. Cassini is the only deep space mission to transmit at three radio wavelengths simultaneously (14-, 4- and 1-centimeter).

Evidence for a very interesting south pole came in July and November 2005. Among other things, the imaging team found large dark cracks that are young and seem to be continually replenished with ice, and a plume of icy material emanating from the surface and may be a geyser-like event.

Pioneer 11 flew by Saturn in 1979, and the Voyagers visited in 1980 and 1981, but no spacecraft ever orbited Saturn--or its moons--until Cassini.

28 April Enceladus Flyby page:
http://saturn.jpl.nasa.gov/mission/flybys/enceladus20100428/

RSS Saturnian ring occultation drawing:
http://saturn.jpl.nasa.gov/spacecraft/cassiniorbiterinstruments/instrumentscassinirss/images/rss1.gif

[Christopher K.]

T-69
On Saturday (5 June) the Cassini spacecraft will fly by Saturn's moon Titan. The craft will be passing 2,044 kilometers above the surface.

A mosaic of Kraken Mare will be obtained if weather conditions are correct. If Kraken Mare is a true lake and completely filled it would be almost five times the size of the Earth's Lake Superior. It has been determined that the shoreline of Kraken Mare has been stable over the last three years.

A mosaic of an area north of Adiri will be also be attempted.The resolution will be 10 kilometers per pixel. Adiri is a bright region 1700 kilometers wide at the equator on Titan's anti-Saturn side.

March Adiri image:
http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=3904

[Christopher K.]

E-11
On 13 August Cassini will fly to within 2500 kilometers of Enceladus. The goal of this pass is to use the CIRS instrument to measure the temperature of Enceladus' "tiger stripes".

The Composite Infrared Spectrometer's 50-cm telescope detects heat (infrared light) and then measures the strengths of various wavelengths. Its average operating power is 26.37 watts. The idea is to use CIRS to map both Saturn's and Titan's global temperature and global gas composition.

The "tiger stripes" are warm fractures in Enceladus' surface.

About CIRS:
http://saturn.jpl.nasa.gov/spacecraft/cassiniorbiterinstruments/instrumentscassinicirs/

Tiger Stripes Image:
http://saturn.jpl.nasa.gov/photos/imagedetails/?imageid=3013

[Christopher K.]

T-72

On 24 September (a Friday), Cassini will pass 8,175 kilometers from Titan. It will map the region known as Belet with 5km/pixel resolution. These mosiacs will be added to the ones created during flybys T-66 and T-67. Afterward, VIMS will perform a global mapping looking for clouds near the poles.

The Visual and Infrared Mapping Spectrometer has two cameras, one for visual wavelengths and one for infrared. It takes pictures in 352 different colors simultaneously, with wavelengths between 300 and 5100 nanometers (billionths of a meter). Aiming VIMS at the cloud decks will probably yield a good amount of information since clouds have different optical properties at different wavelenths.

Belet is basically a "sea of sand" and contains dark dunes, lighter dune-free areas and hills will a "wrinkly radial pattern" (JPL's phrase).

More about VIMS:
http://wwwvims.lpl.arizona.edu/Howitworks.html

Belet in black-and-white and color-coded:
http://nix.larc.nasa.gov/info;jsessionid=26e35tesa0cj3?id=PIA11829&orgid=10