I know I said in my previous post that the Solar System is not a vortex (and it’s not) but that doesn’t mean there are no vortexes in the Solar System—in fact, thanks to the churning atmospheres of the gas giants, it’s full of them! And that’s no better demonstrated than at the poles of Saturn, where giant hurricane-like storms spin away year after year, powered by atmospheric convection and the rapid rotation of the planet.
I’ve often posted about the vortex at the north pole of Saturn—and yes it’s quite impressive—but there’s also a similar feature at Saturn’s south pole as well, albeit a bit more subtle and much less turbulent. The image above is a color view, made from raw data acquired in red, green, blue, and polarized light by NASA’s Cassini spacecraft on July 15, 2008. That was a just over a year before Saturn’s spring equinox and the planet’s south pole was moving into shadow, but still had enough illumination for Cassini to capture some images.
Check out a more direct view down into the vortex below:
An incredible 1,200-mile-wide vortex of spiraling clouds swirling above Saturn’s north pole is seen in all its glory in this stunning image from NASA’s Cassini spacecraft, originally captured last year but recently released by NASA on April 29.
Taking advantage of a new orbital trajectory that puts it high above Saturn’s rings and poles, Cassini acquired the near-infrared images used to make this composite back on Nov. 27, 2012. The resulting image is false color — our eyes aren’t sensitive to those particular wavelengths of light — but still no less amazing!
Vodpod videos no longer available.
There are places surprisingly close by that are the coldest known spots in the entire solar system: on our Moon’s south pole lie deep craters that never receive direct sunlight, in fact have never seen the Sun, and within these craters lie pockets of ice that contain the same frozen material they’ve had since forming over 4 billion years ago. This was the impetus behind NASA’s LCROSS mission, which sent a rocket to strike a permanently-shadowed lunar crater and observe via separate orbiter what sorts of material was kicked up by the impact. The result: water ice, and a surprising lot of it, as well as a considerable amount of other elements! Locked in a deep freeze for billions of years – at nearly -400º F – these craters are time capsules holding mementos from our solar system’s youth.
The animation above, produced by NASA’s Goddard Space Flight Center, shows just how these craters manage to hide from the Sun. As the Moon rotates and revolves around the Earth its angle never varies enough to allow light into its deepest southern craters. Anything in them would in effect have been shielded from direct light forever; the Moon, lacking an atmosphere, does not have scattered light like we have on Earth. Light is either direct or reflected off surfaces, but not diffused within a layer of air. And light on the Moon equals heat, so a shadowed area is freezing cold – much colder, in fact. If the light never comes, then anything in the shadow remains frozen.
The animation was made from image maps obtained by Japan’s Selene KAGUYA probe, a successful 2009 mission that mapped the lunar surface in astonishing HD. At the scheduled completion of its mission KAGUYA gradually lost altitude and eventually impacted the lunar surface on June 10, 2009.
Read more about this and other similar animations on the Goddard media site here.
Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio. Digital Elevation Map (DEM) data of the lunar south pole provided by the JAXA/Selene.
As Saturn’s spring approaches, its north pole comes into view and reveals the curious six-sided geometric shape rotating in its uppermost latitudes. This image was taken by Cassini one month ago. (The image was black-and-white….I colored it myself using the hues found in Saturn’s atmosphere. Click to see the original photo.)
The hexagonal feature is a phenomenon caused by the high wind speeds encircling the pole (300+ mph) and the convective heat processes from deep within the atmosphere, combined with the rotation of the giant gas planet. The hexagon appears to be a deep trough within the high layers of clouds, a clear channel extending 40-50 miles down into the atmosphere. It maintains its geometric shape even while strong winds and storms circle around it…watch it in motion here, filmed in heat-sensitive infrared on October 30, 2006.
This curious feature will be studied further as more of the pole comes into sunlight as Saturn progresses into its spring season. (Saturn’s seasonal rotation takes 29 Earth years to complete, so there’s plenty of time for study.)
Image credit: NASA/JPL/Space Science Institute