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.


 
 

 
VG01

Space tourism rocket explodes in desert

MOJAVE, Calif. – A Virgin Galactic space tourism rocket exploded Oct. 31 during a test flight, killing a pilot aboard and seriously injuring another while scattering wreckage in Southern California’s Mojave Desert, ...
 
 

Headlines October 29, 2014

News: Unmanned rocket explodes just six seconds after taking off - A NASA rocket due to be visible across the East Coast on its way to the International Space Station has blown up on the Launchpad. IG: Former chief of wounded warrior office broke law, DOD regs - The Defense Department inspector general has recommended “corrective action”...
 
 

News Briefs October 29, 2014

F-35C makes first landing at Virginia Beach Navy base The Navy says an operational F-35C joint strike fighter has landed at Naval Air Station Oceana for the first time. Naval Air Station Oceana is the Navy’s master jet base on the East Coast. The Navy says the plane came to the Virginia Beach base Oct....
 

 

Time to turn to American technology for space launch

For the first time since the Cold War, the United States has deployed armored reinforcements to Europe. To counter Russia’s aggression, several hundred troops and 20 tanks are now in the Baltic. Yet the U.S. military is still injecting millions into the Russian military industrial complex. In late August, the United Launch Alliance – the...
 
 
Air Force photograph by Joe Davila

Boeing, Air Force demonstrate Minuteman III readiness in flight test

Air Force photograph by Joe Davila Boeing supported the launch of an unarmed Minuteman III intercontinental ballistic missile at Vandenberg Air Force Base, Calif., on Sept. 23, 2014. Boeing supported the U.S. Air Force’s succ...
 
 

Pentagon going to court for refusing to release Sikorsky data

PETALUMA, Calif. – The Pentagon is refusing to release any data on any prime contractors participating in the 25-year-old Comprehensive Subcontracting Plan Test Program. The American Small Business League launched a program in 2010 to expose the fraud and abuse against small businesses the CSPTP had allowed. As a test the ASBL requested the most...
 




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>