The rings of Neptune are bright in forward-scattered light,
as in the image above, and that indicates that the rings
contain significant amounts of dust. The ring particles are
as dark as those that circle Uranus, so they probably also
contain methane-rich ice darkened by radiation.Visual-wavelength imageNeptuneNeptuneThe brightness of Neptune is hidden behind the black
bar in this Voyager 2 image. Two narrow rings are visible,
and a wider, fainter ring lies closer to the planet. More ring
material is visible between the two narrow rings.When
Neptune occulted
stars, astronomers
sometimes detected rings and
sometimes did not. From that they
concluded that Neptune might have ring
arcs. Computer enhancement of this Voyager
2 visual-wavelength image shows arcs,
regions of higher density, in the outer ring.The ring arcs visible in the outer ring appear
to be generated by the gravitational influence
of the moon Galatea, but other moons must
also be present to confine the rings.When
Neptune occulted
stars, astronomers
sometimes detected rings and
sometimes did not. From that they
concluded that Neptune might have ring
arcs. Computer enhancement of this Voyager
2 visual-wavelength image shows arcs,
regions of higher density, in the outer ring.The ring arcs visible in the outer ring appear
to be generated by the gravitational influence
of the moon Galatea, but other moons must
also be present to confine the rings.Neptune’s rings lie in the plane of the
planet’s equator and inside the
Roche limit. The narrowness of the
rings suggests that shepherd
moons must confine them,
and a few such moons have
been found among the
rings. There must be
more undiscovered
small moons to
confine the rings
completely.Like
the rings of
the other Jovian
planets, the ring
particles that orbit
Neptune cannot have
survived since the formation of
the planet. Occasional impacts
on Neptune’s moons must scatter
debris and resupply the rings with
fresh particles.Like
the rings of
the other Jovian
planets, the ring
particles that orbit
Neptune cannot have
survived since the formation of
the planet. Occasional impacts
on Neptune’s moons must scatter
debris and resupply the rings with
fresh particles.Neptune’s rings have been given names
associated with the planet’s history. English
astronomer Adams and French astronomer LeVerrier
predicted the existence of Neptune from the motion
of Uranus. The German astronomer Galle discovered
the planet in 1846 based on LeVerrier’s prediction.GalleLeVerrierAdamsGalateaDespinaThalassaNaiadArcDisk of
NeptuneNASA
NASAEnhanced visual image4
5
4a4b4cArc