Rings of neptune

Rings can consist of ice particles coated with silicates or carbon -based material - most likely, it gives them a reddish tint ^[1] .

The relatively narrowest, outermost, located 63,000 km from the center of the planet is the Adams ring; Le Verrier ring at a distance of 53,000 km from the center and wider; the weaker Halle ring is 42,000 km away. The Arago Ring is 57,000 km away. From the outer borders of the Le Verrier ring to the inner borders of the Arago ring, there is a wide Lassell ring ^[2] .

The first ring of Neptune was discovered in 1968 by a team of astronomers led by Edward Gwynan ^{[3] [4]} . But later it was believed that this ring could be incomplete, defective ^[5] . Such an opinion prevailed after observing the coverage of the star’s rings in 1984 , when the rings eclipsed the star during its entrance into the shadow, and not upon leaving it ^[6] . The 1989 Voyager 2 images solved this problem, as several more weak rings were found, but with a fairly massive structure ^[7] . The reason for this has not yet been elucidated so far, but this could happen due to gravitational interaction with small satellites in orbit near the rings ^[8] . The most distant Adams ring is now known to contain 5 “arcs” called: “Courage”, “Liberté”, “Egalité 1”, “Egalité 2”, and “Fraternité” ( Liberty, Equality 1, Equality 2 and the Brotherhood ) ^[9] . The existence of these arcs was difficult to explain, because the laws of mechanics predict that they would have to connect into a homogeneous ring in a fairly short time. It was believed that the gravitational influence of the satellite of Neptune - Galatea , which revolves around Neptune near the inner boundary of the Adams ring ^{[10] [11],} holds in this position of the arc. However, new studies show that the influence of Galatea's gravity is not enough to hold the material of the rings in the position in which it is now. The observed results can be explained by the presence of another Neptune satellite, which can be quite small (up to 6 km), and therefore may not yet be discovered ^[12] . Observations from the surface of the Earth, published in 2005 , showed that the rings of Neptune are much more unstable than previously thought. Images taken by the Keck Observatory (Hawaiian Islands) in 2002 and 2003 show significant changes compared to the Voyager 2 images. In particular, it seems that the Liberté arc may disappear in just a century ^[13] .