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NASA Probe Gets Close Views of
Large Saturn Hurricane [video]
NASA's
Cassini spacecraft has provided scientists the first close-up, visible-light views of a behemoth hurricane swirling around Saturn's north pole.This is a narrated video about the hurricane-like storm seen at Saturn's north pole by NASA's Cassini spacecraft.
The eye stretches about 1,250 miles across and the thin, bright clouds at the hurricane's outer edge are whipping by at 330 miles per hour.
It is locked around Saturn's north pole, at about 89 degrees latitude."
NASA/JPL-Caltech/
SSI
http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20130429
.html
PASADENA,
Calif. - NASA's Cassini spacecraft has provided scientists the first close-up, visible-light views of a behemoth hurricane swirling around Saturn's north pole.
In high-resolution pictures and video, scientists see the hurricane's eye is about 1,250 miles (2,
000 kilometers) wide, 20 times larger than the average hurricane eye on
Earth. Thin, bright clouds at the outer edge of the hurricane are traveling 330 mph(
150 meters per second). The hurricane swirls inside a large, mysterious, six-sided weather pattern known as the hexagon.
"We did a double take when we saw this vortex because it looks so much like a hurricane on Earth," said
Andrew Ingersoll, a
Cassini imaging team member at the
California Institute of Technology in
Pasadena. "But there it is at Saturn, on a much larger scale, and it is somehow getting by on the small amounts of water vapor in Saturn's hydrogen atmosphere."
Scientists will be studying the hurricane to gain insight into hurricanes on Earth, which feed off warm ocean water. Although there is no body of water close to these clouds high in Saturn's atmosphere, learning how these
Saturnian storms use water vapor could tell scientists more about how terrestrial hurricanes are generated and sustained.
Both a terrestrial hurricane and Saturn's north polar vortex have a central eye with no clouds or very low clouds. Other similar features include high clouds forming an eye wall, other high clouds spiraling around the eye, and a counter-clockwise spin in the northern hemisphere.
A major difference between the hurricanes is that the one on Saturn is much bigger than its counterparts on Earth and spins surprisingly fast. At Saturn, the wind in the eye wall blows more than four times faster than hurricane-force winds on Earth. Unlike terrestrial hurricanes, which tend to move, the Saturnian hurricane is locked onto the planet's north pole. On Earth, hurricanes tend to drift northward because of the forces acting on the fast swirls of wind as the planet rotates.
The one on Saturn does not drift and is already as far north as it can be.
"The polar hurricane has nowhere else to go, and that's likely why it's stuck at the pole," said Kunio Sayanagi, a Cassini imaging team associate at
Hampton University in
Hampton, Va.
Scientists believe the massive storm has been churning for years. When Cassini arrived in the Saturn system in 2004, Saturn's north pole was dark because the planet was in the middle of its north polar winter. During that time, the Cassini spacecraft's composite infrared spectrometer and visual and infrared mapping spectrometer detected a great vortex, but a visible-light view had to wait for the passing of the equinox in
August 2009. Only then did sunlight begin flooding Saturn's northern hemisphere. The view required a change in the angle of Cassini's orbits around Saturn so the spacecraft could see the poles
...
Cassini changes its orbital inclination for such an observing campaign only once every few years. Because the spacecraft uses flybys of Saturn's moon
Titan to change the angle of its orbit, the inclined trajectories require attentive oversight from navigators. The path requires careful planning years in advance and sticking very precisely to the planned itinerary to ensure enough propellant is available for the spacecraft to reach future planned orbits and encounters.
The
Cassini-Huygens mission is a cooperative project of NASA, the
European Space Agency and the
Italian Space Agency.
JPL, a division of the California Institute of Technology, Pasadena, manages the Cassini-Huygens mission for NASA's
Science Mission Directorate in
Washington. The
Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team consists of scientists from the
United States, the
United Kingdom,
France and
Germany. The imaging operations center is based at the
Space Science Institute in
Boulder, Colo.
For more information about Cassini and its mission, visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .
- published: 02 May 2013
- views: 29400