HUBBLE DISCOVERS A DARK CLOUD IN THE ATMOSPHERE OF URANUS (STScI-PRC06-47)

FOR RELEASE: 1:00 pm (EDT) September 28, 2006


PHOTO NO.: STScI-PRC06-47

HUBBLE DISCOVERS A DARK CLOUD IN THE ATMOSPHERE OF URANUS

Just as we near the end of the hurricane season in the Atlantic Ocean, winds whirl and
clouds churn 2 billion miles away in the atmosphere of Uranus, forming a dark vortex
large enough to engulf two-thirds of the United States. Astronomers at the University
of Wisconsin-Madison used NASA's Hubble Space Telescope to take the first definitive
images of a dark spot on Uranus. The elongated feature measures 1,100 miles by 1,900
miles (1,700 kilometers by 3,000 kilometers). This three-wavelength composite image
was taken with Hubble's Advanced Camera for Surveys on August 23, 2006. The research
team found the dark spot again on August 24. The inset image shows a magnified view of
the spot with enhanced contrast. Uranus's north pole is near the 3 o'clock position in this
image. The bright band in the southern hemisphere is at 45 degrees south.

To see and read more about this research on the Web, visit:
http://hubblesite.org/news/2006/47

Credit: NASA, ESA, L. Sromovsky and P. Fry (University of Wisconsin), H. Hammel (Space
Science Institute), and K. Rages (SETI Institute)

For images and additional information about Uranus's dark spot on the Web, visit:
http://hubblesite.org/news/2006/47

For more information, contact:

Ray Villard
Space Telescope Science Institute, Baltimore, Md.
(Phone: 410-338-4514; E-mail: )

Lawrence Sromovsky
University of Wisconsin, Madison, Wis.
(Phone: 608-263-6785; E-mail: )

Heidi B. Hammel
Space Science Institute, Boulder, Colo.
(Phone: 203-438-3506; E-mail: )

Kathy Rages
SETI Institute, Mountain View, Calif.
(E-mail: )

Patrick Fry
University of Wisconsin, Madison, Wis.
(E-mail: )

The Hubble Space Telescope is a project of international cooperation between
NASA and the European Space Agency (ESA). The Space Telescope Science
Institute in Baltimore conducts Hubble science operations. The Institute is
operated for NASA by the Association of Universities for Research in Astronomy,
Inc., Washington.