A new moon called Hippocamp, named after a mythological equine sea creature had been previously overlooked by other spacecraft as it is only 34 kilometres in diameter and has a tight orbit around the blue giant, going around the planet once a day.
Hippocamp is one of the seven inner moons of Neptune who orbit the planet once every day. When the Voyager 2 spacecraft passed by Neptune in 1989, it discovered six moons in Neptune’s inner orbit, yet missed Hippocamp because of its dimness and suboptimal camera angles. The other seven satellites of Neptune are located at more of a distance and have trajectories that are more irregular.
After 30 years a team led by Mark Showalter, a senior research scientist at the SETI (Search for Extraterrestrial Intelligence) Institute, pinpointed Hippocamp in images captured by the Hubble Space Telescope. The team published their findings on Wednesday in Nature magazine.