Tethys Flyby - September 2005
23 Sep 2005The Tethys flyby is technically non-targeted (meaning there are no manoeuvres solely designed to control the flyby trajectory); however, through efforts recently made by the Cassini navigation team, this encounter was able to be lowered to allow for a close study of the icy moon.
This encounter is set up with two manoeuvres: an apoapsis manoeuvre on 19 September, and an approach manoeuvre, on 23 September.
The closest approach to Tethys occurs on Saturday, 24 September, at 02:42 UT at an altitude of 1500 km above the surface and at a speed of 9 kilometres per second. The flyby is outbound from Saturn, with periapsis occurring on 23 September. This is the fifth close encounter with Saturn's icy satellites, after Phoebe and three Enceladus encounters (in orbit 3, non-targeted; orbit 4 and orbit 11).
Key questions about Tethys that this encounter's activities hope to unlock include:
This encounter should offer spectacular views of Ithaca Chasma.
Tethys Surface Coverage
This map of the surface of Saturn's moon Tethys illustrates the regions that will be imaged by Cassini during the spacecraft's close flyby of the moon on 24 September 2005. At closest approach, the spacecraft is expected to pass approximately 1500 kilometres above the moon's surface. The coloured lines delineate the regions that will be imaged at differing resolutions, listed in the legend at bottom.
The new high-resolution coverage will reveal details on the Saturn-facing hemisphere of Tethys, including parts of the giant Ithaca Chasma canyon system. Imaging scientists also are hoping to obtain images of an ancient ridge east of Ithaca Chasma, as well as a section of terrain just west of the giant rift that appeared to be unusually smooth in NASA Voyager images. This flyby is also focused on gathering high-resolution imaging data of the moon's southern polar region.
The map was made from images obtained by both the Cassini and Voyager spacecraft.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.