Uranus is the fourth largest planet in mass and third largest in radius in the solar system. It is the seventh planet from the sun. Uranus and Neptune have similar composition. The scientists classify Neptune and Uranus as ice giants to differentiate them from gas giants Saturn and Jupiter. Uranus is composed of more ice such as water, methane, ammonia with little helium and hydrogen gases. It is also the planet with the coldest atmosphere having a temperature of -224 degrees Celsius. In addition, Uranus rings system has a unique configuration because its axis is tilted sideways.
Uranus has rings like other gas planets. It has 13 faint rings with Epsilon ring as the brightest. Edward W. Dunham, Jessica Mink, and James L. Elliot discovered the rings on March 10, 1977. The rings are also dark with fine dust and large particles of ten meters diameter.
Uranus rings are classified as, 4, 5, 6, α, 1986U2R/ζ, β, γ, δ, η, λ, ε, μ and v. They are composed of dark radiation-processed organics and water ice. The μ ring has a radius of 98,000km while the 1986U2R/ has a radius of 38,000km.
Classification Of Uranus rings
Uranus rings fall into three groups based on size, location, and composition. There are the narrow main rings, outermost rings, and the dusty rings.
The narrow main rings
The ε ring is the densest and brightest in the Uranus ring system. It has a maximum or minimum brightness ratio of 2.5 to 3.0. The ring’s geometric thickness is estimated to be 150 meters.
The δ ring is slightly inclined and circular in shape. It shows unique variations in width and optical depth. The ring has a wave-like structure.
The γ ring is dense and narrow. Its width ranges from 3.6 km to 4.7 km. The ring’s normal optical depth ranges from 0.7 to 0.9 meters.
The η ring has two components: a broad outer shoulder with low optical depth and a narrow optical dense component. The broad component is geometrically thicker than the narrow component. In some areas, the narrow component vanishes.
The rings 6, 5, and 4
The 6, 5, and 4 rings are the fainter and innermost of Uranus’s narrow rings. They measure 1.6-2.2 km, 1.9-4.9 km, and 2.4-4.4 km wide.
Voyager 2 discovered the λ ring in 1986. It is faint and narrow located in the ε ring. The λ ring has an optical length of 0.2 to 0.2 km at wavelength of 2.2 um. The λ ring changed dramatically and became the brightest on Uranus ring system. This was discovered in the forward-scattered light in 1986.
The 1986U2R/ζ ring is broad and faint lying in the ring 6. It was detected in 1986 by Voyager 2 and has an optical depth of 10-3. The ring lies between 37,000 and 39,000 km from the Uranus center.
The outer ring system (μ and v rings)
The Hubble Space Telescope detected the outer ring system in
2003 to 2005. The outer rings are 3,800 km and 17,000 km wide. They are also
very faint and broad. In addition, the rings have a normal peak optical depth
of 5.4x10-6 and 8.5x10-6. Furthermore, the outer rings
possess a triangular radial brightness profiles.