Uranus: gallery

Uranus, rings, and moons

Figure 1.

Uranus crescent

Figure 2.

Uranus rings

Figure 3.


Figure 4.

Figure 1


These two false-color images taken with the Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) in the near-infrared reveal six distinct clouds on Uranus. The right-hand image, taken 90 minutes after the left-hand image, shows the planet's rotation. At near-infrared wavelengths, absorption by gases in the Uranian atmosphere limits the view to different altitudes, causing intense contrasts and colors. In these images, the blue exposure probes the deepest atmospheric levels. A blue color indicates clear atmospheric conditions, prevalent at mid-latitudes near the center of the disk. The green exposure is sensitive to absorption by methane, indicating a clear atmosphere; but in hazy atmospheric regions, the green color is seen because sunlight is reflected back before it is absorbed. The green color around the south pole (marked by "+") shows a strong local haze. The red exposure reveals absorption by hydrogen, the most abundant gas in the atmosphere of Uranus. Most sunlight shows patches of haze high in the atmosphere. A red color near the limb of the disk indicates the presence of a high-altitude haze. The purple color to the right of the equator also suggests haze high in the atmosphere with a clear atmosphere below. The five clouds visible near the right limb rotated counterclockwise during the time between both images. They reach high into the atmosphere, as indicated by their red color. Features of such high contrast have never been seen before on Uranus. The clouds are almost as large as continents on Earth. Another cloud rotated along the path is shown by a white arrow and is located at lower altitudes, as indicated by its green color. The rings of Uranus are extremely faint in visible light but quite prominent in the near infrared. The brightest ring, the epsilon ring, has a variable width around its circumference. Its widest and thus brightest part is at the top in this image. Two fainter, inner rings are visible next to the epsilon ring. Eight of the small Uranian satellites, discovered by Voyager 2, can be seen in both images.


Figure 2


A view of Uranus taken by Voyager 2 as it headed away from the planet. This image is the result of combining the data obtained through three color filters.


Figure 3


This dramatic Voyager 2 picture reveals a continuous distribution of small particles throughout the Uranus ring system. Voyager took this image while in the shadow of Uranus, at a distance of 236,000 kilometers (142,000 miles) and with a resolution of about 33 kilometers (20 miles). This unique geometry – the highest phase angle at which Voyager imaged the rings – allows us to see lanes of fine dust particles not visible from other viewing angles. All the previously known rings are visible here however, some of the brighest features in the image are bright dust lanes not previously seen. The combination of this unique geometry and a long, 96-second exposure allowed this spectacular observation, acquired through the clear filter of Voyager's wide-angle camera. The long exposure produced a noticeable, non-uniform smear as well as streaks due to trailed stars.


Figure 4


A false-color view of the rings of Uranus made from images taken by Voyager 2 on January 21, 1986, from a distance of 4.17 million kilometers (2.59 million miles). Nine genuine rings are visible; the fainter, pastel lines seen between them are artifacts of computer enhancement.