Saturn III
Tethys [TEE-this] was discovered by Giovanni Cassini in 1684. It is an icy body similar in nature to Dione and Rhea. The density of Tethys is 1.21 gm/cm^3 indicating that it is composed almost entirely of water-ice. Tethys's icy surface is heavily cratered and contains cracks caused by faults in the ice. There is one enormous trench on Tethys about 65 km wide and extending from above the center to the extreme left. It covers three-fourths of Tethys' circumference. The fissure is about the size scientists would predict if Tethys were once fluid and its crust hardened before the interior. The canyon has been named Ithaca Chasma. A vast expanse of relative young plains also exists on Tethys. Tethys' surface temperature is -187° C (-305° F).
Discovered by ..................... Giovanni Domenico Cassini Date of discovery ...................................... 1684 Mass (kg) .......................................... 7.55e+20 Mass (Earth = 1) ................................. 1.2634e-04 Equatorial radius (km) .................................. 530 Equatorial radius (Earth = 1) .................... 8.3098e-02 Mean density (gm/cm^3) ................................. 1.21 Mean distance from Saturn (km) ...................... 294,660 Rotational period (days) ........................... 1.887802 Orbital period (days) .............................. 1.887802 Mean orbital velocity (km/sec) ........................ 11.36 Orbital eccentricity ................................. 0.0000 Orbital inclination .................................... 1.09° Escape velocity (km/sec) .............................. 0.436 Visual geometric albedo ................................. 0.9 Magnitude (Vo) ......................................... 10.2 Mean surface temperature ............................. -187°C
Tethys
(GIF, 241K)
This view of Tethys was taken by Voyager 2 on August 26, 1981.
It is the highest resolution image acquired by the Voyager space
craft. An enormous trench named Ithaca Chasma extends from the
left side of this image to the upper center.
(Credit: Calvin J. Hamilton, Los Alamos National Laboratory)
Tethys Color Composite
(GIF, 101K)
This view of Tethys is a color composite of three images
taken by Voyager 2 on August 25, 1981.
(Credit: Calvin J. Hamilton, Los Alamos National Laboratory)
Saturn
Enceladus
Telesto & Calypso
