6th Largest Moon of Uranus - Puck (12th Moon outwards from Uranus)

Puck is the largest inner moon of Uranus and the sixth largest of the Uranus moons. Puck is the 35th largest moon in the Solar System currently known.



Discovery

Puck was discovered by Stephen P. Synnott, who is an American astronomer and Voyager scientist, from the images taken by Voyager 2 on 30 December 1985.



Naming

The moon was given the temporary designation S/1985 U1.

It was later named after the Puck who appears in Shakespeare's A Midsummer Night's Dream, a little sprite who travels around the globe at night with the fairies. In Celtic mythology and English folklore, a Puck is a mischievous sprite, imagined as an evil demon by Christians.

Stats

Diameter: 162 km

Semi-major axis: 86,004 km

Orbital Period: 0.76 days

Orbit

Puck takes as long to rotate on its axis as it does to make one orbit of Uranus; and therefore always keeps the same hemisphere pointed to Uranus.

The orbit of Puck lies between the rings of Uranus and the first of Uranus' large moons, Miranda.

Physical characteristics

Puck is approximately spherical in shape, has a dark heavily cratered surface, and is grey in color.

There are three named craters on the surface of Puck, the largest being about 45 km in diameter. Observations with Hubble Space Telescope and large terrestrial telescopes found water ice absorption features in the spectrum of Puck.

Nothing is known about the internal structure of Puck. It is probably made of a mixture of water ice with the dark material similar to that found in the rings. This dark material is probably made of rocks or radiation processed organics.

The absence of craters with bright rays implies that Puck is not differentiated meaning that ice and non-ice components have not separated from each other forming a core and mantle.

Exploration Status

So far the only close-up images of Puck have been from the Voyager 2 probe, which photographed the moon during its flyby of Uranus in January 1986.

No other spacecraft has ever visited the Uranian system or Puck, and no mission is planned in the foreseeable future.