| |
 |
|
|
Science Forum Index » Geology - Meteorology Forum » NASA Sees Into The Eye of a Monster Storm on Saturn
Page 1 of 1
|
| Author |
Message |
| Guest |
 Posted: Thu Nov 09, 2006 2:56 pm |
|
|
|
|
Nov. 9, 2006
Erica Hupp/Dwayne Brown
Headquarters, Washington
202-358-1237/1726
Carolina Martinez
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-9382
RELEASE: 06-344
NASA SEES INTO THE EYE OF A MONSTER STORM ON SATURN
NASA's Cassini spacecraft has seen something never before seen on
another planet -- a hurricane-like storm at Saturn's South Pole with
a well-developed eye, ringed by towering clouds.
The "hurricane" spans a dark area inside a thick, brighter ring of
clouds. It is approximately 5,000 miles across, or two thirds the
diameter of Earth.
"It looks like a hurricane, but it doesn't behave like a hurricane,"
said Andrew Ingersoll, a member of Cassini's imaging team at the
California Institute of Technology, Pasadena. "Whatever it is, we're
going to focus on the eye of this storm and find out why it's there."
A movie taken by Cassini's camera over a three-hour period reveals
winds around Saturn's South Pole blowing clockwise at 350 miles per
hour. The camera also saw the shadow cast by a ring of towering
clouds surrounding the pole, and two spiral arms of clouds extending
from the central ring. These ring clouds, 20 to 45 miles above those
in the center of the storm, are two to five times taller than the
clouds of thunderstorms and hurricanes on Earth.
Eye-wall clouds are a distinguishing feature of hurricanes on Earth.
They form where moist air flows inward across the ocean's surface,
rising vertically and releasing a heavy rain around an interior
circle of descending air that is the eye of the storm itself. Though
it is uncertain whether such moist convection is driving Saturn's
storm, the dark "eye" at the pole, the eye-wall clouds and the spiral
arms together indicate a hurricane-like system.
Distinctive eye-wall clouds have not been seen on any planet other
than Earth. Even Jupiter's Great Red Spot, much larger than Saturn's
polar storm, has no eye or eye-wall, and is relatively calm at the
center.
This giant Saturnian storm is apparently different than hurricanes on
Earth because it is locked to the pole and does not drift around like
terrestrial hurricanes. Also, since Saturn is a gaseous planet, the
storm forms without an ocean at its base.
In the Cassini imagery the eye looks dark at light wavelengths where
methane gas absorbs the light and only the highest clouds are
visible.
"The clear skies over the eye appear to extend down to a level about
twice as deep as the usual cloud level observed on Saturn," said
Kevin H. Baines, of Cassini's visual and infrared mapping
spectrometer team at NASA's Jet Propulsion Laboratory, Pasadena,
Calif. "This gives us the deepest view yet into Saturn over a wide
range of wavelengths, and reveals a mysterious set of dark clouds at
the bottom of the eye."
Infrared images taken by the Keck I telescope in Mauna Kea, Hawaii,
had previously shown Saturn's South Pole to be warm. Cassini's
composite infrared spectrometer has confirmed this with higher
resolution temperature maps of the area. The spectrometer observed a
temperature increase of about 4 degrees Fahrenheit at the pole. The
instrument measured high temperatures in the upper troposphere and
stratosphere, regions higher in the atmosphere than the clouds seen
by the Cassini imaging instruments.
"The winds decrease with height, and the atmosphere is sinking,
compressing and heating over the South Pole," said Richard
Achterberg, a member of Cassini's composite infrared spectrometer
team at NASA's Goddard Spaceflight Center, Greenbelt, Md.
Observations taken over the next few years, as the South Pole season
changes from summer to fall, will help scientists understand the role
seasons play in driving the dramatic meteorology at the south pole of
Saturn.
The Cassini-Huygens mission is a cooperative project of NASA, the
European Space Agency and the Italian Space Agency. The Jet
Propulsion Laboratory manages the Cassini-Huygens mission for NASA's
Science Mission Directorate, Washington.
For a movie, high-resolution images, infrared images and Saturn
temperature maps, visit:
http://www.nasa.gov/cassini
-end- |
|
|
| Back to top |
|
| Prai Jei |
| Posted: Fri Nov 10, 2006 4:00 pm |
|
|
|
Guest
|
baalke@earthlink.net (or somebody else of the same name) wrote thusly in
message <1163098562.578890.231730@h48g2000cwc.googlegroups.com>:
Quote: NASA's Cassini spacecraft has seen something never before seen on
another planet -- a hurricane-like storm at Saturn's South Pole with
a well-developed eye, ringed by towering clouds.
Could I ask a question which none of the accounts of this discovery have
made clear. Was this storm already in progress when Saturn's south pole was
first photographed, or has it developed since Cassini was around? What I am
wondering is, could it be a *permanent* feature of Saturn, never noticed
before because nothing has ever photographed Saturn's poles before?
--
Terms and conditions apply. Batteries not included. Subject to status.
Always read the label.
Interchange the alphabetic letter groups to reply |
|
|
| Back to top |
|
| |
|
Page 1 of 1
All times are GMT - 5 Hours
The time now is Wed Jul 09, 2008 2:19 am
|
|
