Space

December 6, 2013

NASA’s Cassini Spacecraft obtains best views of Saturn Hexagon

NASA’s Cassini spacecraft has obtained the highest-resolution movie yet of a unique six-sided jet stream, known as the hexagon, around Saturn’s north pole.

This is the first movie of its kind, using color filters, and the first to show a complete view of the top of Saturn down to about 70 degrees latitude. Spanning about 20,000 miles across, the hexagon is a wavy jet stream of 200-mph winds with a massive, rotating storm at the center. There is no weather feature exactly, consistently like this anywhere else in the solar system.

“The hexagon is just a current of air, and weather features out there that share similarities to this are notoriously turbulent and unstable,” said Andrew Ingersoll, a Cassini imaging team member at the California Institute of Technology in Pasadena. “A hurricane on Earth typically lasts a week, but this has been here for decades – and who knows – maybe centuries.”

Weather patterns on Earth are interrupted when they encounter friction from land forms or ice caps. Scientists suspect the stability of the hexagon has something to do with the lack of solid land forms on Saturn, which is essentially a giant ball of gas.

Better views of the hexagon are available now because the sun began to illuminate its interior in late 2012. Cassini captured images of the hexagon over a 10-hour time span with high-resolution cameras, giving scientists a good look at the motion of cloud structures within.

They saw the storm around the pole, as well as small vortices rotating in the opposite direction of the hexagon. Some of the vortices are swept along with the jet stream as if on a racetrack. The largest of these vortices spans about 2,200 miles, or about twice the size of the largest hurricane recorded on Earth.

Scientists analyzed these images in false color, a rendering method that made it easier to distinguish differences among the types of particles suspended in the atmosphere – relatively small particles that make up haze – inside and outside the hexagon.

“Inside the hexagon, there are fewer large haze particles and a concentration of small haze particles, while outside the hexagon, the opposite is true,” said Kunio Sayanagi, a Cassini imaging team associate at Hampton University in Virginia. “The hexagonal jet stream is acting like a barrier, which results in something like Earth’s Antarctic ozone hole.”

The Antarctic ozone hole forms within a region enclosed by a jet stream with similarities to the hexagon. Wintertime conditions enable ozone-destroying chemical processes to occur and the jet stream prevents a resupply of ozone from the outside. At Saturn, large aerosols cannot cross into the hexagonal jet stream from outside and large aerosol particles are created when sunlight shines on the atmosphere. Only recently, with the start of Saturn’s northern spring in August 2009, did sunlight begin bathing the planet’s northern hemisphere.

“As we approach Saturn’s summer solstice in 2017, lighting conditions over its north pole will improve, and we are excited to track the changes that occur both inside and outside the hexagon boundary,” said Scott Edgington, Cassini deputy project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

A black-and-white version of the imaging camera movie and movies obtained by Cassini’s visual and infrared mapping spectrometer also are tools Cassini scientists can use to look at wind speeds and the mini-storms inside the jet stream.

Cassini launched in 1997 and arrived at Saturn on July 1, 2004. Its mission is scheduled to end in September 2017. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA’s Science Mission Directorate in Washington. JPL designed, developed and assembled the Cassini orbiter and its two onboard cameras. The imaging team is based at the Space Science Institute, Boulder, Colo.

The movies are available online at http://go.usa.gov/Wtrk.




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


 
 

 

Headlines January 23, 2015

News: Yemen chaos threatens U.S. counterterror efforts, including drone programĀ - The White House’s strategy for fighting al-Qaeda in Yemen – repeatedly presented as a model by President Obama – was left in tatters Thursday by the resignation of the man who personally approved U.S. drone strikes in the country and the collapse of its central...
 
 

News Briefs January 23, 2015

NATO detects key Russian military equipment in east Ukraine NATO’s top commander in Europe says the alliance has detected the presence of key Russian military equipment in eastern Ukraine that, in the past, has accompanied large inflows of Russian troops. Gen. Philip Breedlove told a news conference Jan. 22 in Brussels that Russian electronic warfare...
 
 
Boeing photograph

Boeing Maritime Surveillance Aircraft ready for demonstration flights

Boeing photograph The Boeing Maritime Surveillance Aircraft program is ready for customer demonstration flights, having completed the baseline ground and flight testing of the aircraft mission systems. The Boeing Maritime Surve...
 

 
Air Force photograph by Jacqueline Cowan

F135 test demonstrates success of AEDC workshare initiative

Air Force photograph by Jacqueline Cowan Aerospace Testing Alliance Test Engineer Darren Carroll, pictured in front, assists as Pratt & Whitney Test Engineer Ronnie Thomas does a borescope inspection of the fan on the F135 ...
 
 
U.S. Air Force photo by Master Sgt. Kevin J. Gruenwald

40 years of Red Flag at Nellis

U.S. Air Force photo by Master Sgt. Kevin J. Gruenwald A flight of F-15 Eagles and F-16 Fighting Falcons Aggressors fly in formation over the Nevada Test and Training Ranges June 5, 2008. The proposal for Red Flag came in early...
 
 
Lockheed Martin photograph

Navy gears up to order production of 29 aircraft diagnostic systems

Lockheed Martin photograph Petty Officers Third Class Ira Schwartz assigned to Fleet Readiness Center Southeast at Naval Air Station Jacksonville, Fla., left, and Devin Riley from Fleet Readiness Center Mid-Atlantic at Naval Ai...
 




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>