written by: Anurag Ghosh•edited by: George Adcock•updated: 4/27/2010
The rings of Neptune were first discovered by a team of astronomers in 1968. The first close-up images were sent by the Voyager 2 during its Neptune flyby in 1989. Here are some of the most interesting facts and information about the enigmatic rings of Neptune.
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Saturn, Uranus and Jupiter—these three giant planets have rings around them, but what about Neptune? Does it have rings? Yes, Neptune does possess a set of rings, but they are fainter and smaller than the rings around neighboring planets. Neptune has five rings named after notable astronomers who have contributed to the discovery of Neptune. The names of the rings of Neptune are:
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The Discovery of the Rings of Neptune
One of Neptune’s rings was first discovered in 1968 by Edward F. Guinan, a research scientist, and his team. However, because of the planet’s distance, nothing could be ascertained about the ring. In the early 1980s, astronomers observed Neptune when it passed between a star and the Earth—a phenomenon called stellar occultation. It occurs when a star’s light gets blocked by a planet, moon, or asteroid from reaching an observer. Basically, scientists observe stellar occultations to analyze a planet’s ring systems or its atmosphere.
After observing the stellar occultation five times, scientists perceived a slight “blink" from the star before or after Neptune covered it. They came to a conclusion that the rings around the planet were blocking the star’s light from reaching them. In 1989, NASA’s Voyager 2 flyby revealed several faint rings around the planet. The spacecraft sent back pictures, which gave a closer view of the planet’s rings. The images also gave an idea about the composition of the rings. Currently, sophisticated telescopes allow scientists to see some of Neptune’s rings, although the faintest cannot be seen with the most powerful telescopes.
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What are the Rings Around Neptune Made Of?
The rings of Neptune are made up of dust, ice particles and organic compounds, which give the rings a reddish hue. The dust particles are probably due to small meteorites that smashed into the planet’s moons.
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Some Interesting Facts About Neptune’s Rings
The Adams ring is named after the British astronomer John Couch Adams, who predicted Neptune’s existence and position only using his mathematical calculations.
Also called 1989 NIR, the narrow Adams ring contains five arcs named Liberté, Egalité 1, Egalité 2, Fraternité and Courage. The names of the arc were borrowed from the popular French Revolution phrase which means Liberty (Liberté) Equality (Égalité) and Brotherhood (Fraternité).
The arcs look more solid than the rest of the planet’s rings, but strangely don’t spread throughout the Adam’s Ring. Scientists believe that the arcs’ gravitational interactions with Galatea, one of Neptune’s 13 moons, are responsible for this phenomenon.
The rings of Neptune are quite younger than the Solar System’s age. They were created when one of Neptune’s inner moons was destroyed by the planet’s gravity.
The Galle ring is named after astronomer Johann Gottfried Galle, who first discovered Neptune using his telescope. It is the planet’s innermost ring that extends to a width of 1242.74 miles (2000 kilometers).
The narrowest ring is LeVerrier and the widest ring is Lassell. The LeVerrier ring is only 70.21 miles (113 kilometers) wide and the Lassell is approximately 2485.48 miles (4,000 kilometers) wide.