Nation Neptune’s new moon Hippocamp is so tiny that it wasn’t detected in 1989 during flyby, scientists report February 20, 2019 Doyle Rice, USA TODAY Comments Off on Neptune’s new moon Hippocamp is so tiny that it wasn’t detected in 1989 during flyby, scientists report A new moon has been found near Neptune, joining the other 13 we knew about. It's so small that it wasn't detected during the 1989 Voyager 2 flyby.