When NASA ’s Voyager 2 visited Neptune in 1989 , it discovered six moons closer to the satellite than its large moon , Triton . Now , stargazer can add a new one to the roster , force the full number of Sun Myung Moon around the ice behemoth to 14 .
The in vogue plus is called Hippocamp , after the mythologic seahorse , and it is the belittled moon of the system at only 34 km ( 21 miles ) across . It was first seen in 2013 using archival icon from the Hubble Space Telescope that were snapped from 2004 onwards . It was officially designated as the fourteenth moonlight of Neptune on September 2018 .
The long delay between the first range and confirmation had to do with the advanced imaging technique necessary to study such a diminutive moon . After all , the uranologist were studying an object not much prominent than a city at a space of 4.6 billion kilometers ( 2.9 billion miles ) . The team that made the discovery , led by Mark Showalter from the SETI Institute , have devoted three Hubble reflection polish to study Hippocamp and the other internal lunar month of Neptune .
As reported in theirNaturepaper , the squad trust that Hippocamp provide further evidence that the inner moons have been shaped and possibly organize by a series of impact . They conceive that Hippocamp might have been a fragment of Proteus – the secondly - largest lunar month in the whole system – and was released after a cometary encroachment .
The airfoil of Proteus is heavily cratered and atypical with a 150 - klick ( 93 - international mile ) crater , call Pharos . Hippocamp would answer for for only 2 percentage of the mass ejected by the impact that organise the Pharos crater , so more material could be shroud in a ringing or a yet - to - be - distinguish synodic month . Hippocamp ’s orbit lies 105,000 kilometers ( 65,200 miles ) from Neptune but only 12,000 kilometers ( 7,500 land mile ) from Proteus , a fact that strengthens the relationship between the two object .
The seven internal moons would be , under this scenario , immature than Neptune . It is believed that Neptune had a system of moon when it shape , but then it captured Triton , which was at the time a dwarf satellite - like body . The entry of such a monolithic object in the organisation caused havoc , ruin the original moons and organize a disk of debris from which the other moons come forth .
Hippocamp is the first moon to be discover around Neptune since Psamathe in 2003 .
