Telesto [tah-LESS-toh] and Calypso [ka-LIP-so] are called the Tethys Trojans because they circle Saturn in the same orbit as Tethys, about 60 degrees ahead of and behind that body. Telesto is the leading Trojan and Calypso is the trailing Trojan. Both were found in 1981 by B. Smith through ground-based observations made in 1980. Telesto is 34 by 28 by 26 kilometers (21 by 17 by 16 miles) and Calypso is 34 by 22 by 22 kilometers (21 by 14 by 14 miles).
Discovered by ............................. B. Smith & others Date of discovery ...................................... 1980 Mass (kg) ................................................. ? Radius (km) ........................................ 17x14x13 Radius (Earth = 1) ............................... 2.6654e-03 Mean density (gm/cm^3) .................................... ? Mean distance from Saturn (km) ...................... 294,660 Rotational period (days) .................................. ? Orbital period (days) ................................ 1.8878 Mean orbital velocity (km/sec) ........................ 11.36 Orbital eccentricity ................................... 0.00 Orbital inclination ..................................... 0.0° Visual geometric albedo ................................. 0.5 Magnitude (Vo) ......................................... 18.7
Discovered by ............................. B. Smith & others Date of discovery ...................................... 1980 Mass (kg) ................................................. ? Radius (km) ........................................ 17x11x11 Radius (Earth = 1) ............................... 2.6654e-03 Mean density (gm/cm^3) .................................... ? Mean distance from Saturn (km) ...................... 294,660 Rotational period (days) .................................. ? Orbital period (days) ................................ 1.8878 Mean orbital velocity (km/sec) ........................ 11.36 Orbital eccentricity ................................... 0.00 Orbital inclination ..................................... 0.0° Visual geometric albedo ................................. 0.6 Magnitude (Vo) ......................................... 18.0