Hippocamp is a small moon of Neptune about 35 km in diameter. It orbits the planet in just under one Earth day. Its discovery in July, 2013, brought the number of Neptune’s known satellites to 14. Hippocampus is so dim that it was not notices when Voyager 2 flew by Neptune in 1989. It was detected by analyzing archived Neptune photographs taken by the Hubble Space Telescope.
This animation shows how Hippocamp might look close up.
Video Credit: ESA