Rings of Neptune

Rings of Neptune

The rings of Neptune consist of five principal rings. The Adams ring includes five distinct arcs, named Fraternité, Égalité 1 and 2, Liberté, and Courage. Neptune also has a faint unnamed ring coincident with the orbit of the moon Galatea. Three other moons orbit between the rings: Naiad, Thalassa and Despina.

About Rings of Neptune in brief

Summary Rings of NeptuneThe rings of Neptune consist primarily of five principal rings. The Adams ring includes five distinct arcs, named Fraternité, Égalité 1 and 2, Liberté, and Courage. Neptune also has a faint unnamed ring coincident with the orbit of the moon Galatea. Three other moons orbit between the rings: Naiad, Thalassa and Despina. The rings are made of extremely dark material, likely organic compounds processed by radiation, similar to those found in the rings of Uranus. Neptune’s rings are named after astronomers who contributed important work on the planet: Galle, Le Verrier, Lassell, Arago, and Adams. In addition to these well-defined rings, Neptune may also possess an extremely faint sheet of material stretching inward to the Galle ring, and possibly farther in toward the planet. Three of the Neptunian rings are about 100km wide, with widths of 100km or less; in contrast, the Adams ring is between 2,000 and 5,000km wide. Neptune possesses five distinct rings named in order of increasing distance from the planet, in order from Galle to Lassell to Arago. Neptune is fainter than Uranus, but its rings are still far below visibility threshold. The Voyager 2 spacecraft made the definitive discovery of the rings during its fly-by of Neptune in 1989, passing by as close as 4,950 km above the planet’s atmosphere on 25 August. They are now visible with the Hubble Space Telescope and Earth-based telescopes, owing to advances in resolution and light-gathering power.

The glare from the rings is significantly reduced, at methane-absorbed wavelengths in which the rings are significantly reduced from the background glare from Neptune is significantly less than 0.1%. The rings of Saturn’s C ring are comparable to the less dense portions of Saturn’s main rings such as the C ring and the Cassini Division, but much of Neptune’s ring system is quite tenuous, faint and dusty, more closely resembling the ring of Jupiter. They were first discovered in 1984 by Patrice Bouchet, Reinhold Häfner and Jean Manfroid at La Silla Observatory in Chile during an observing program proposed by André Brahic and Bruno Sicardy from Paris Observatory, and at Cerro Tololo Interamerican Observatory by F. Vilas and L. -R. Elicer for a program led by William Hubbard. The first reliable detection of a ring was made in 1968 by stellar occultation, although that result would go unnoticed until 1977 when the rings Of Uranus were discovered. In the 1980s, significant occultations were much rarer for Neptune than for Uranus because Neptune lay near the Milky Way and was thus moving against a denser field of stars. It was found that the occultation was due to the small Neptuneian moon Larissa, a highly unusual event.