Except for Triton, known since Neptune's discovery in 1846, and the new moon S/2004 N 1, they were discovered in 1989 by NASA's Voyager 2 spacecraft. (NASA, ESA, and A. Feild/STScI) ...

Neptune as seen by Voyager 2 during its flyby in 1989. Photo / NASA/JPL-Caltech/Kevin M. Gill A diminutive nugget of a moon has been discovered lurking in the inner orbit of Neptune. The moon ...

Nereid, Neptune's third largest moon was found in 1949. Images taken by NASA's Voyager 2 spacecraft unveiled the second largest moon, Proteus, and five smaller moons, Naiad, Thalassa, Despina, Galatea ...

For one, Triton is big. It's the seventh-largest moon in the solar system, and it's over 200 times bigger than all of the other moons of Neptune combined, which makes it really stick out.

New Horizons flew past Neptune and its moon Triton in 2014 from a distance of about 2.45 billion miles (3.96 billion kilometers), but also just zoomed past the planet.