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 January 28, 2015

News: Panel will propose new military retirement system - The long-awaited report on military compensation set to drop Thursday will propose fundamental changes to military retirement and health care benefits, according to several people familiar with the report. Source: DOD to request $585 billion for fiscal 2016 - The Department of Defense is preparing to submit a...
 
 

News Briefs January 28, 2015

Defense contractor to pay $2 million to settle claims A Northern California defense contractor will pay the federal government $2 million to settle claims about its manufacturing of parts for remote-controlled aircraft. The U.S. Attorney’s Office in Sacramento says Sacramento-based Composite Engineering Inc. agreed to pay the money to end allegations that it artificially inflated...
 
 
Navy photograph

USS Roosevelt marks 200,000 trap

Navy photograph An F/A-18F Super Hornet flown by Capt. Daniel Grieco, commanding officer of the aircraft carrier USS Theodore Roosevelt (CVN 71), and Capt. Benjamin Hewlett, deputy commander of Carrier Air Wing (CVW) 1, complet...
 

 
Navy photograph by PO1 William Larned

USS California returns from maiden deployment

Navy photograph by PO1 William Larned The Virginia-class attack submarine USS California (SSN 781) returns from its maiden deployment to its homeport at Naval Submarine Base New London. Under the command of Cmdr. Shawn Huey, Ca...
 
 
Army photograph

Army proves new watercraft capabilities

Army photograph Marine Corps assets are loaded onto the USNS Sgt. Matej Kocak (T-AK 3005), from an U.S. Army Landing Craft Utility, or LCU, USAV Port Hudson during port operations, at White Beach Naval Base, Jan. 22, 2015. Sold...
 
 

Orbital stockholders approve merger with ATK’s aerospace, defense groups

Orbital Sciences Corporation announced Jan. 27 that at a special meeting, the company’s stockholders voted overwhelmingly to approve the proposed merger with the Aerospace and Defense Groups of Alliant Techsystems Inc., pursuant to the definitive transaction agreement dated April 28, 2014. Approximately 99 percent of the votes cast at the special meeting voted in favor...
 




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>