176 km
ESTIMATED DIAMETER
0.429 DAYS
ORBITAL PERIOD
61,953 km
AVERAGE DISTANCE FROM NEPTUNE
1989
DISCOVERED
INNER
MOON TYPE
RING SHEPHERD
ROLE
THE RING SHEPHERD
Galatea is a small inner moon of Neptune
and one of the moons located closest to
the planet.
It was discovered in 1989 in images
returned by Voyager 2 during its historic
encounter with Neptune.
Galatea is especially interesting because
its gravity interacts with Neptune's faint
ring system.
The moon is believed to help confine and
shape the narrow Adams Ring, acting as
one of the gravitational influences that
maintains the ring's structure.
Galatea has an irregular shape and a dark
surface, typical of many small outer
Solar System moons.
GALATEA FEATURES
RING SHEPHERD
Galatea's gravity helps influence the
structure and confinement of Neptune's
faint Adams Ring.
INNER MOON
Galatea orbits relatively close to Neptune,
completing one revolution in less than
half an Earth day.
VOYAGER 2
Galatea was discovered in Voyager 2
images during the spacecraft's 1989
flyby of Neptune.
DID YOU KNOW?
Galatea's gravity helps shape Neptune's
faint Adams Ring, making this
small moon an important part of the
Neptune ring system.
THE MOON THAT HELPS SHAPE A RING
Galatea orbits close to Neptune and is dynamically connected with the planet's Adams ring. Its gravity helps confine material associated with the ring's unusual arc structures through orbital resonances.
This makes Galatea a useful example of a shepherd moon: even a relatively small satellite can influence the distribution and stability of particles in a planetary ring system.
IMAGE:
NASA / JPL / VOYAGER 2
GALATEA IMAGE VIA WIKIMEDIA COMMONS
GALATEA IMAGE VIA WIKIMEDIA COMMONS