Cassini images bizarre hexagon on Saturn
2007 03 29
An odd, six-sided, honeycomb-shaped feature circling the entire north pole of Saturn has captured the interest of scientists with the Cassini mission.
This atmospheric feature was already imaged by NASA’s Voyager 1 and 2 spacecraft over two decades ago. The fact that it has appeared in Cassini images indicates that it is a long-lived feature. A second hexagon, significantly darker than the brighter historical feature, is also visible in the Cassini pictures. The spacecraft's visual and infrared mapping spectrometer (VIMS) is the first instrument to capture the entire hexagon feature in one image.
“This is a very strange feature, lying in a precise geometric fashion with six nearly equally straight sides,” said Kevin Baines, atmospheric expert and member of Cassini’s visual and infrared mapping spectrometer (VIMS) team at NASA’s Jet Propulsion Laboratory, Pasadena, California. “We’ve never seen anything like this on any other planet. Indeed, Saturn’s thick atmosphere where circularly-shaped waves and convective cells dominate is perhaps the last place you’d expect to see such a six-sided geometric figure, yet there it is.”
The hexagon is similar to Earth’s polar vortex, which has winds blowing in a circular pattern around the polar region. On Saturn, the vortex has a hexagonal rather than circular shape. The hexagon is nearly 25 000 kilometres across. Nearly four Earths could fit inside it.
The new images taken in thermal-infrared light show the hexagon extends much deeper down into the atmosphere than previously expected, some 100 kilometres below the cloud tops. A system of clouds lies within the hexagon. The clouds appear to be whipping around the hexagon like cars on a racetrack.
“It’s amazing to see such striking differences on opposite ends of Saturn’s poles,” said Bob Brown, team leader of the Cassini VIMS instrument, University of Arizona, Tucson. “At the south pole we have what appears to be a hurricane with a giant eye, and at the north pole of Saturn we have this geometric feature, which is completely different.”
The Saturn north pole hexagon has not been visible to Cassini’s visual cameras, because it’s winter in that area, so the hexagon is under the cover of the long polar night, which lasts about 15 years. The infrared mapping spectrometer can image Saturn in both daytime and nighttime conditions and see deep inside. It imaged the feature with thermal wavelengths near 5 microns (seven times the wavelength visible to the human eye) during a 12-day period beginning on 30 October 2006. As winter wanes over the next two years, the feature may become visible to the visual cameras.
“Through the use of different wavelengths, the VIMS instrument is able to probe Saturn’s atmosphere at different depths,” says Angioletta Coradini, from the Istituto di Fisica dello Spazio Interplanetario by INAF (Italy), and member of the VIMS team. “Thanks to the VIMS measurements we can link together atmospheric structures – such as the hexagonal vortex – with the energetic balance of the planet’s upper atmosphere,” she continued. “With this series of investigations – the very first ever performed at Saturn – we are obtaining vital information to understand the atmospheric dynamics of giant planets in general.”
Based on the new images and more information on the depth of the hexagonal feature on Saturn, scientists think it is not linked to Saturn’s radio emissions or to auroral activity, as once contemplated, even though Saturn’s northern aurora lies nearly overhead. So, there is still plenty to do for the scientists to solve the puzzle.
“This will be possible thanks to the exceptional capability of instruments of this kind in probing planetary atmospheres and following their evolution with time, in a true ‘3D’ way,” added Coradini. “As a comparison, it is a similar instrument (VIRTIS) sitting on board ESA’s Venus Express, that is providing the most detailed view ever of Venus’ double-eyed south-polar vortex on Venus.”
Saturn's 'hexagon' appears to have remained fixed with the planet’s rotation rate and axis since first glimpsed by Voyager 26 years ago. The actual rotation rate of Saturn is still uncertain. “Once we understand its dynamical nature, this long-lived, deep-seated polar hexagon may give us a clue to the true rotation rate of the deep atmosphere and perhaps the interior,” concluded Baines.
Article from: http://www.esa.int/SPECIALS/Cassini-
Liquid Water on Enceladus - The Source of Saturns rings?
Blue Rings Pose New Mystery
Saturn’s Monstrous Polar Storm
The Saturn Theory (pdf)
Frequency Fields at the Cellular Level
Evolution linked to Spiritual Renaissance: DNA Called “Antennae to God” (See Hexagon)
Latest News from our Front Page
Military Says No Presidential Authorization Needed To Quell “Civil Disturbances”
2013 05 17
A recent Department of Defense instruction alters the US code applying to the military’s involvement in domestic law enforcement by allowing US troops to quell “civil disturbances” domestically without any Presidential authorization, greasing the skids for a de facto military coup in America along with the wholesale abolition of Posse Comitatus.
The instruction (embedded at the end of this article), which ...
Ancient Maya Pyramid Destroyed in Belize
2013 05 17
An archaeological group says it plans to take legal action.
Despite its small size, the Caribbean country of Belize is known for a few outstanding characteristics: a spectacular barrier reef, a teeming rain forest, and extensive Maya ruins.
It now has one fewer of those ruins.
A construction company in Belize has been scooping stone out of the major pyramid at the site ...
Ginger: A Warming Herb
2013 05 17
Ginger is an Asian herb that is particularly well known to us in the West. Over time, and with trial and error, its stimulating properties and piquant flavor have been integrated into both our herbal “materia medica” and cuisine.
Brewed as an herbal tea, ginger root is particularly helpful for those people who have underactive stomachs and difficulty producing adequate amounts ...
Australian man dead for 40 minutes revived with new CPR machine
2013 05 17
In an Australian first, doctors have used a new resuscitation technique to revive three patients who were clinically dead for up to an hour.
One of the lucky survivors was Colin Fiedler, 49, who was pronounced dead at The Alfred Hospital in Melbourne, Victoria, after suffering a heart attack, The Herald Sun reported.
Doctors brought Fieldler back to life using a U.S.-made ...
How a pregnancy test for humans caused a wave of global extinctions
2013 05 17
The deadly fungus Batrachochytrium dendrobatidis has been wiping out amphibian species across the globe for decades. But how did this global environmental disaster get started? A new study suggests that it came from doctors importing frogs for use in pregnancy tests.
Since the 1980s, amphibian species have experienced a sharp decline in their numbers. Some estimates suggest that 400 or more ...
|More News » |