Moons of Neptune
Triton, in Greek mythology the
son of Poseidon, is the largest of Neptune's fourteen
confirmed natural satellites and with a diameter of 2,700 kilometers is
almost ¾ the size of Luna the moon of Earth.
It has a tenuous almost non-existent atmosphere composed mainly of
nitrogen and methane and a surface temperature of -240 Celsius, but
because it is geologically active (its surface is covered in ice
volcanoes) there is a possibility of aquatic life existing beneath its
is unique amongst large moons in that it's in a retrograde orbit with
its primary (it orbits in a direction opposite to the planet's
rotation), but tidal interactions are slowly causing the orbit's decay,
and predictions are that some 3.6 billion years from now the moon will
pass Neptune's Roche limit  disintegrate and form a ring system
similar to Saturn's.
The 13 minor
moons, being small, lack the mass/self-gravity necessary to
assume a spherical shape:
irregularly shaped and with a diameter of 418 km is the second largest
of Neptune's satellites.
irregularly shaped, has a diameter of 340 km and is possibly a captured
asteroid or Kuiper belt object.
irregularly shaped and has a diameter of 193 km.
irregularly shaped and has a diameter of 158 km.
irregularly shaped and has a diameter of 148 km.
irregularly shaped and has a diameter of 80 km.
irregularly shaped and has a diameter of 58 km.
irregularly shaped and has a diameter of 62 km.
irregularly shaped and has a diameter of 44 km.
irregularly shaped and has a diameter of 42 km.
is irregularly shaped, has a diameter of 60 km and with an orbit of 48
million killometers is the outermost of Neptune's satellites.
is irregularly shaped and with a diameter of only 38 killometers the
second smallest. It and Neso are further from their primary than any
other moons in the Solar System and are suspected to have been, at one
time, part of a larger common object.
N 1 (provisional) the latest and smallest of Neptune's moons was
discovered accidentally by Mark Showalter an astronomer at the SETI
Institute while perusing old Hubble images. The moon is 20 km (12
miles) in diameter (so small and faint Voyager 2 failed to spot it
while surveying the Neptunian system in 1989). The newly found
satellite is located between Larissa and Proteus.
The Roche limit/radius is the minimum distance at which a small
celestial body can orbit a second more massive celestial body (usually
a satellite and its primary) before being torn apart by tidal forces.
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