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 August 1, 2015

News: Marine F-35 jets deemed ready for combat – A small batch of the highly anticipated – and much criticized – F-35B Joint Strike Fighter jets have been approved for combat by the U.S. Marine Corps.   News: Reports: China to sell J-10 fighter to Iran, Syria? – Iran is rumored external link to be buying 150...
 
 

News Briefs August 3, 2015

Russian military helicopter crashes during air show, one dead A Russian military helicopter crashed Aug. 2 during an aerobatic display, killing one of its crewmembers and injuring another, the Defense Ministry said. The Mi-28 helicopter gunship was part of a flight of helicopters performing aerobatics at the Dubrovichi firing range in Ryazan region, about 170...
 
 
Army photograph by John Andrew Hamilton

Improved Multiple Launch Rocket System tested at White Sands Missile Range

Army photograph by John Andrew Hamilton A Multiple Launch Rocket System with an improved armored cab fires a training rocket during a test. The rockets were simple training rockets and not equipped with a warhead, but still gen...
 

 

Missile Defense Agency, Raytheon demonstrate SM-6’s new anti-ballistic missile defense capability

In a first-of-its-kind test, the U.S. Navy fired a Raytheon Standard Missile-6, intercepting and destroying a short-range ballistic missile target at sea. The successful U.S. Missile Defense Agency test proved a modified SM-6 can eliminate threat ballistic missiles in their final seconds of flight. “SM-6 is the only missile in the world that can do...
 
 

Northrop Grumman-developed stealthy data link validated as combat ready with U.S. Marine Corps

the U.S. Marine Corps achieving F-35B initial operating capability, the Multifunction Advanced Data Link waveform developed by Northrop Grumman has been proven a key combat-ready capability of the F-35 Lightning II program. MADL is a high-data-rate, directional communications link that allows fifth-generation aircraft to communicate and coordinate tactics covertly. During testing of the Lockhee...
 
 

Lockheed Martin technology helps pilots, UAS operators share data, stay safe

As Unmanned Aircraft Systems take to the skies, it is essential for safety that UAS operators and pilots are aware of each other. To help provide this shared situational awareness, Lockheed Martin has deployed the first components of a UAS traffic management system that is available to the UAS community now. Lockheed Martin’s online Flight...
 




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=""> <s> <strike> <strong>