Montage of Uranus' five largest satellites. From top to bottom in order of decreasing distance from Uranus are Oberon, Titania, Umbriel, Ariel, and Miranda. Images are presented to show correct relative sizes and brightness. Coverage is incomplete for Miranda and Ariel; gray circles depict missing areas.

Voir l'image PIA01361: Uranus - Montage of Uranus' Five Largest Satellites sur le site de la NASA.

PIA01975: Uranus - Family Portrait

This "family portrait" of Uranus' five largest moons was compiled from images sent back Jan. 20, 1986, by the Voyager 2 spacecraft. The pictures were taken through a clear filter from distances of 5.0 million to 6.1 million kilometers (3.1 million to 3.8 million miles). In this comparison, we see the relative sizes and relativities of the satellites. From left, in order of increasing distance from the planet, they are Miranda, Ariel, Umbriel, Titania and Oberon. The two largest, Oberon and Titania, are about half the size of Earth's Moon, or roughly, 1,600 kilometers (1,000 miles) in diameter. Miranda, smallest of the five, has about one-quarter to one-third the diameter. Even in these distant views, the satellites exhibit distinct differences in appearance. On average, Oberon and Titania reflect about 20 percent of the sunlight, Umbriel about 12 percent, Ariel and Miranda about 30 percent. Ariel shows the largest contrast on its surface, with the brightest areas about 25 percent. All five satellites show only slight color variations on their surfaces, with their average color being very nearly gray. The best views of the satellites will be obtained Jan. 24, the day of closest approach. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

Voir l'image PIA01975: Uranus - Family Portrait sur le site de la NASA.

PIA02963: Hubble Finds Many Bright Clouds on Uranus

A recent Hubble Space Telescope view reveals Uranus surrounded by its four major rings and by 10 of its 17 known satellites. This false-color image was generated by Erich Karkoschka using data taken on August 8, 1998, with Hubble's Near Infrared Camera and Multi-Object Spectrometer. Hubble recently found about 20 clouds—nearly as many clouds on Uranus as the previous total in the history of modern observations.

The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Space Flight Center for NASA's Office of Space Science.

This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/.

Voir l'image PIA02963: Hubble Finds Many Bright Clouds on Uranus sur le site de la NASA.

PIA01357: Uranus moon - 1985U1

Several craters are seen on the surface of 1985U1, one of several small moons of Uranus discovered by Voyager 2. The spacecraft acquired this single image -- the only close-up it obtained of any of the new moons -- on Jan. 24, 1986. At the time, Voyager was at a distance of about 500,000 kilometers (300,000 miles) from 1985U1, yielding a resolution of about 10 km (6 mi) in this clear-filter, narrow-angle image. The moon was found Dec. 3O, 1985; it was the first and largest of nearly a dozen satellites discovered by the spacecraft cameras. This image shows 1985U1 to be a dark, nearly spherical object, with a diameter of about 150 km (90 mi); the dark surface reflects only 7 percent of the incident light. The picture was inserted into the Voyager encounter sequence late in its development. This image has had a complex history, having been recorded on the spacecraft tape recorder and first played back during the late afternoon of Jan. 24. An antenna-pointing problem at one of the Australian tracking stations led to loss of the data, so the image had to be transmitted a second time. It was successfully received shortly before 6 p.m. PST Jan. 26. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

Voir l'image PIA01357: Uranus moon - 1985U1 sur le site de la NASA.