Nereid is the outermost known satellite of Neptune. It was discovered in 1949 by G. Kuiper. Its mean radius is 170km and it is a very faint object as its magnitude is 18. With an orbital period of 360 days and a highly eccentric orbit, it remains outside the field of view of Neptune.

Dennis Simmons, from Brisbane, Australia, has shot this picture showing the motion trail over a 140 minute exposure as an integration of 7 subframes.

by Dennis Simmons on 2009-08-27 12:52:43 [Original Size] - [Next Image] - [Author's gallery]