Uranus: Gallery
Hubble Space Telescope image. Jul. 28,
1997
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. |
Voyager 2 image.
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. |
Voyager 2 image
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
km (142,000 mi.) and with a resolution of about 33 km (20 mi.). 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. |
Voyager 2 image. Jan. 21, 1986
A false-color view of the rings of Uranus made from images taken by
Voyager 2 on Jan. 21, 1986, from a distance of 4.17 million km (2.59
million mi.). Nine genuine rings are visible; the fainter, pastel
lines seen between them are artifacts of computer enhancement. |
Related category
• PLANETS
AND MOONS
Also on this site:
Encyclopedia
of Alternative Energy & Sustainable Living
Encyclopedia
of History
BACK TO TOP
|
