Space

April 29, 2013

NASA probe gets close-up views of large hurricane on Saturn

nasa-hurricane
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 miles per hour (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, Cassini’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.

“Such a stunning and mesmerizing view of the hurricane-like storm at the north pole is only possible because Cassini is on a sportier course, with orbits tilted to loop the spacecraft above and below Saturn’s equatorial plane,” said Scott Edgington, Cassini deputy project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “You cannot see the polar regions very well from an equatorial orbit. Observing the planet from different vantage points reveals more about the cloud layers that cover the entirety of the planet.”

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 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.




All of this week's top headlines to your email every Friday.


 
 

 

Headlines April 24, 2015

News: More than $1 billion in U.S. emergency reconstruction aid goes missing in Afghanistan - A total of $1.3 billion that the Pentagon shipped to its force commanders in Afghanistan between 2004 and 2014 for the most critical reconstruction projects can’t be accounted for by the Defense Department, 60 percent of all such spending under an...
 
 

News Briefs April 24, 2015

German defense minister: widely used rifle has no future A widely used assault rifle has “no future” with the German military in its current form, Germany’s defense minister said April 22, escalating a dispute over the weapon’s alleged shortcomings. Ursula von der Leyen said last month that a study showed the G36 rifle has a...
 
 
Army photograph

Composites key to tougher, lighter armaments

Army photograph XM-360 test firing at Aberdeen Proving Ground, Md., in 2007, is shown. The Army is on the cusp of revolutionizing materials that go into armament construction, making for stronger, lighter and more durable weapo...
 

 

Northrop Grumman signs long-term agreement with Raytheon

Northrop Grumman has entered a long-term agreement with Raytheon to supply its LN-200 Inertial Measurement Unit for Raytheon optical targeting systems. The long-term agreement with Raytheon’s Space and Airborne Systems business extends through 2018. The LN-200 provides camera stabilization on optical targeting systems that conduct long-range surveillance and target acquisition for various...
 
 

NTTR supports first F-35B integration into USMC’s weapons school exercise

The Nevada Test and Training Range was part of history April 21, when four U.S. Marine Corps-assigned F-35B Lightning IIs participated in its first Marine Corps’ Final Exercise of the Weapons and Tactics Instructor course on the NTTR’s ranges. The Final Exercise, or FINEX, is the capstone event to the U.S. Marine Corps Marine Aviation...
 
 
AAR-Textron

AAR awarded new contract from Bell Helicopter Textron to support T64 engines

AAR announced April 22 that Bell Helicopter Textron Inc. awarded its Defense Systems & Logistics business unit a contract providing warehouse and logistics services in support of upgrading T64 engines for the Bell V-280 Val...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>