6th Largest Moon of Neptune - Despina (3rd Moon outwards from Neptune)

Despina as seen by Voyager 2 (smeared horizontally)

Despina is the third closest inner satelliteis, the sixth largest satellite of Neptune and the 38th largest moon in the Solar System currently known.

Discovery

Despina was discovered in late July 1989 from the images taken by the Voyager 2 spacecraft.

Naming

The moon was given the temporary designation S/1989 N3.

Despina the moon was named after Despoina, a nymph who was a daughter of Poseidon and Demeter.

In Greek mythology, Despoina, Despoena or Despoine, was the daughter of Demeter and Poseidon and sister of Arion. She was the goddess of mysteries of Arcadian cults worshipped under the title Despoina, "the mistress" alongside with her mother Demeter, one of the goddesses of the Eleusinian mysteries.

Stats

Diameter (mean): 150 km

Semi-major axis: 52,526 km

Orbital Period: 0.335 days

Orbit

Despina's orbit lies just inside the Le Verrier ring. As it is also below Neptune's synchronous orbit radius, so it is slowly spiralling inward due to tidal deceleration and may eventually impact Neptune's atmosphere, or break up into a planetary ring upon passing its Roche limit due to tidal stretching.

Despina takes as long to rotate on its axis as it does to make one orbit of Neptune; and therefore always keeps the same hemisphere pointed to Neptune.

Physical characteristics

Despina is irregularly shaped and shows no sign of any geological modification.

Little else is known about Despina. Despina is likely, like the other satellites inward of Triton, a rubble pile re-accreted from fragments of Neptune's original satellites, which were smashed up by perturbations from Triton soon after that moon's capture into a very eccentric initial orbit.