Rhea and Tethys are moons of which planet?
Rhea (moon) is also designated Saturn V (being the fifth major moon going outward from the planet, after Mimas, Enceladus, Tethys, and Dione). Cassini named the four moons he discovered (Tethys, Dione, Rhea, and Iapetus) "Sidera Lodoicea" (the stars of Louis) to honor King Louis XIV. Astronomers fell into the habit of referring to them and Titan as "Saturn I" through "Saturn V". Once Mimas and Enceladus were discovered, in 1789, the numbering scheme was extended to "Saturn VII", and then to "Saturn VIII" with the discovery of Hyperion in 1848, before the numbering scheme was frozen to prevent further confusion. Rhea
Moons of Saturn Of these three moons, only Methone has been photographed at close range, showing it to be egg-shaped with very few or no craters. Trojan moons are a unique feature only known from the Saturnian system. A trojan body orbits at either the leading L or trailing L Lagrange point of a much larger object, such as a large moon or planet. Tethys has two trojan moons, Telesto (leading) and Calypso (trailing), and Dione also has two, Helene (leading) and Polydeuces (trailing). Helene is by far the largest trojan moon, while Polydeuces is the smallest and has the most chaotic orbit.