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This photograph of Saturn was taken by the Cassini spacecraft in December. The rings are completely horizontal, and appear as a razor-thin line in the middle. The shadows of those rings are evident on the planet. And that tiny little ball underneath the plane of the rings? That’s Tethys, a moon of Saturn that is over a thousand kilometers wide. Yes, Saturn is immense, but it takes good pictures. Link
Image: NASA/JPL-CalTech/Space Science Institute
Look closely at the photo above and you can pick out 5 of Saturn's 60 natural satellites (Janus, Pandora, Enceladus, Mimas, and Rhea) as well as the planet's iconic rings:
A quintet of Saturn's moons come together in the Cassini spacecraft's field of view for this portrait.
Janus (179 kilometers, or 111 miles across) is on the far left. Pandora (81 kilometers, or 50 miles across) orbits between the A ring and the thin F ring near the middle of the image. Brightly reflective Enceladus (504 kilometers, or 313 miles across) appears above the center of the image. Saturn's second largest moon, Rhea (1,528 kilometers, or 949 miles across), is bisected by the right edge of the image. The smaller moon Mimas (396 kilometers, or 246 miles across) can be seen beyond Rhea also on the right side of the image.
This view looks toward the northern, sunlit side of the rings from just above the ringplane. Rhea is closest to Cassini here. The rings are beyond Rhea and Mimas. Enceladus is beyond the rings.
The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on July 29, 2011. The view was acquired at a distance of approximately 1.1 million kilometers (684,000 miles) from Rhea and 1.8 million kilometers (1.1 million miles) from Enceladus. Image scale is 7 kilometers (4 miles) per pixel on Rhea and 11 kilometers (7 miles) per pixel on Enceladus.
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This image was selected as the Astronomy Picture of the Day last weekend. It was taken by the Cassini probe in 2006 from the shadow of Saturn.
First, the night side of Saturn is seen to be partly lit by light reflected from its own majestic ring system. Next, the rings themselves appear dark when silhouetted against Saturn, but quite bright when viewed away from Saturn, slightly scattering sunlight, in this exaggerated color image. Saturn’s rings light up so much that new rings were discovered, although they are hard to see in the image. Seen in spectacular detail, however, is Saturn’s E ring, the ring created by the newly discovered ice-fountains of the moon Enceladus and the outermost ring visible above. Far in the distance, at the left, just above the bright main rings, is the almost ignorable pale blue dot of Earth.
You should take a look at the larger version at NASA. Link -via Laughing Squid
(Image credit: Cassini Imaging Team, SSI, JPL, ESA, NASA)
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Discussion about weather is often relegated to the realm of awkward small-talk and complaints about the heat/snow/rain, but extraplanetary weather is a different thing altogether… at least for me. These images of a storm over Saturn’s surface–the largest ever recorded on the planet–are interesting and beautiful. The false color doesn’t hurt, but it’s still so massive that imagining it takes a bit of brain yoga.
First detected in December 2010, the storm has developed from a small spot into a raging storm covering an area about 4 billion square kilometres, or eight times the surface of the Earth, in Saturn’s northern hemisphere.
The false colours on the images mark the different altitudes of clouds: blue clouds reside at the highest altitude with those in red at the lowest. The two high-resolution images at the bottom are mosaics, each made up of 84 images taken over 4.5 hours. The lower of the two was taken 11 hours, or one Saturn day, after the first.
The top two images are enlargements taken from the earlier of the two bottom images. They show the head of the storm (top left) and its turbulent middle (top right). Calculations reveal that the head of the storm is moving west at a speed of about 100 kilometres per hour.
Link | Image: NASA/JPL-Caltech/SSI
What do you get when you pair incredible footage of Saturn and its moons with Nine Inch Nails? An awe inspiring black and white video showing clips NASA’s Cassini spacecraft took during its ongoing mission to the ringed planet.
If you haven’t been following the Cassini spacecraft’s second mission to Saturn, here’s a video that will hook you in. It features incredible black-and-white images of Saturn and its moons, all captured by Cassini’s “camera” — also known as the Cassini-Huygens Imaging Science Subsystem — and designer/director Chris Abbas, who edited together footage from Cassini’s archive and set it to a great Nine Inch Nails soundtrack.
5.6k Saturn Cassini Photographic Animation from stephen v2 on Vimeo.
[Vimeo Link] | Far more impressive if you embiggen (click on the rightmost icon)
We’ve all seen space travel in movies, but the real thing is far, far more beautiful and impressive. Here’s the Cassini spacecraft approaching Saturn in 2004. No CGI, no 3D models – just thousands of images the spacecraft took stitched together by Stephen van Vuuren of SV2 Studios.
Better yet, he’s turning this into an indie IMAX movie called Outside In (can’t wait to see this on the giant screen!) – via APOD
Image: NASA/JPL/University of Arizona/University of Leicester
Earth is not the only planet with the phenomenon of polar lights, Saturn has ‘em too! NASA’s Cassini orbiter captured infrared images that revealed the stunning sights. From National Geographic’s Breaking Orbit Blog:
In the picture, the ring of green auroras might seem faint, but that curtain of light is shooting up about 600 miles (1,000 kilometers) from the cloud tops of Saturn’s south polar region.
In general, astronomers think auroras on Saturn occur via a process similar to the one that creates Earth’s polar lights.
Charged particles from the sun flow along the planet’s magnetic field lines, hitting the upper atmosphere at the poles. There the particles excite (or transfer energy to) atoms in the atmosphere, and the excited atoms release the excess energy as light.
In Saturn’s case, auroras can also be sparked by electromagnetic waves generated when the planet’s moons move through the charged gas that fills Saturn’s magnetosphere, the bubble around the planet created by its magnetic field.
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The disappearance of hydrogen near the surface of Saturn’s moon, Titan, could be evidence of hydrogen breathing lifeforms.
There’s some exciting—and potentially confusing—news coming out of the NASA’s Cassini Saturn orbiter program. Two new papers have come out, both dealing with the possibility that alien life could be theoretically hanging out on Saturn’s moon Titan.
Link via BoingBoing
You thought that Saturn’s moon Mimas looks like the Death Star? The Cassini probe analyzed temperature differences on the surface of Mimas and determined that it is actually Pac-man! Link -via Digg
(image credit: NSA/JPL/SSI)
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The picture above was taken by NASA’s Cassini space probe of Titan, a moon of Saturn. The glint of light at the top of the moon is of a lake — the first non-Earth lake ever seen. In Popular Science, Jeremy Hsu writes:
A haze of methane enshrouds Saturn’s largest moon, Titan, and prevents scientists from seeing most sunlight reflections off the surface. But NASA’s Cassini orbiter managed to snap a stunning image of sunlight glinting off a huge, liquid methane lake — a smoking gun that confirms liquid in the northern hemisphere.
Titan remains the only other planetary body besides Earth known to have liquid on its surface, and appears eerily similar to our world as far as rain and other weather patterns. But instead of liquid water, methane and ethane drizzle down from Titan’s atmosphere and fill the many lakes dotting the moon.
The newly revealed visual and infrared image was taken back on July 8, just as the sun had begun to directly shine upon the northern lakes near the start of spring on Titan. Scientists matched the reflection to the southern shoreline of Kraken Mare, a lake that covers almost 150,000 square miles and sits in the northern hemisphere.
Link | Photo: NASA
This computer-generated animation by Roy Prol imagines the Earth as a ringed planet, such as Saturn or Uranus. First, it addresses the orientation of the rings, and then shows what they would look like from various places around the world, day and night. In Scientific American, John Matson writes that Earth may have once had a ring system:
But such a ring, if it were to suddenly appear, might not be all good news. Decades ago, John O’Keefe of the NASA Goddard Space Flight Center ventured that Earth may have had a ring system similar to Saturn’s for a brief period. In a 1980 paper in Nature, O’Keefe pointed to climatic data indicating colder winters at the end of the Eocene epoch some 34 million years ago along with showers of tektites, glassy rocks of mysterious origin, at around the same time. O’Keefe’s theory held that tektites that missed the Earth in this bombardment were captured into a ring system that may have persisted for millions of years, casting a winter shadow across Earth’s surface and contributing to a late Eocene die-off of many marine organisms such as plankton and mollusks.
Link via Geekologie
There’s a strange hexagon shape at the north pole of the planet Saturn. It was spotted 20 years ago, and Cassini confirms it’s still there. Is it some alien fortress/outpost? Or something surprisingly cooler?
Using infrared, NASA’s Spitzer Space Telescope has spotted an enormous ring encircling Saturn, previously undetected by other telescopes. The ring is likely composed of ice crystals shed by Phoebe, the farthest Saturnian moon. The new ring reaches 11 million miles (18 million km) away from the planet.
“This is one supersized ring,” said Anne Verbiscer, an astronomer at the University of Virginia, Charlottesville. “If you could see the ring, it would span the width of two full moons’ worth of sky, one on either side of Saturn.”
The discovery may help solve an age-old riddle of one of Saturn’s moons. Iapetus has a strange appearance — one side is bright and the other is really dark, in a pattern that resembles the yin-yang symbol… The ring is circling in the same direction as Phoebe, while Iapetus, the other rings and most of Saturn’s moons are all going the opposite way. According to the scientists, some of the dark and dusty material from the outer ring moves inward toward Iapetus, slamming the icy moon like bugs on a windshield.
Cassini looks toward Rhea’s cratered, icy landscape with the dark line of Saturn’s ringplane and the planet’s murky atmosphere as a background. Rhea is Saturn’s second-largest moon, at 1,528 km (949 mi) across. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired on July 17, 2007 at a distance of approximately 1.2 million km (770,000 mi) from Rhea.
Link -via Metafilter
(image credit: NASA/JPL/SSI)
See also: Saturn’s Newest Moon
Surprise! Astronomers analyzing images taken by NASA’s Cassini spacecraft have found that Saturn has yet another moon in one of its outermost rings:
A faint pinprick of light embedded in one of Saturn’s outermost rings is now the 61st moon known to be circling the giant planet, astronomers announced today. [...]
Based on its brightness, astronomers estimate that the as-yet-unnamed moon is a third of a mile (half a kilometer) wide. This is tiny as far as moons go, but the object is likely the largest in its neighborhood.
