NASA has recently revealed newly snapped images of Saturn and all of its breathtaking array of rings, taken as a series of infrared images by the Cassini spacecraft, whilst the sun was situated behind the enormous gas giant.
The infrared images convey Saturn in a radically different light, helping to accentuate some of the nine continuous main rings, primarily formed of icy particles, rocky debris and dust particulate.
Cassini is one of the heaviest and most complicated interplanetary crafts ever conceived, weighing in at over 2,500 kilograms, and boasting an impressive array of instruments. The craft was dispatched aboard Titan IVB/Centaur to observe the Saturn system in 1997, and began performing its duties during 2004. The entire craft comprises of a
probe/lander, called Huygens, designed to explore the surface of Saturn’s Titan moon. Quite remarkably, Huygens was the very first probe to make a landing in the outer Solar System.
The Cassini Spacecraft also marks an incredible feat of ingenuity, designed and manufactured by researchers and engineers from the United States and sixteen European countries. Its current missions are overseen by NASA’s Jet Propulsion Laboratory, where the behemoth craft was assembled by Aérospatiale.
Cassini bares an astonishing array of complex scientific instruments, including several spectrometers, visible-light cameras, a Cosmic Dust Analyzer, an Imaging Science Subsystem, and instruments to measure the strength and direction of the magnetic field of Saturn.
The spacecraft has been investigating the planet for almost a decade, with astronomers still piecing together and interpreting the multi-image picture of the Saturn system. Nonetheless, during a recent press release, the space agency showcased a new infrared strip of Saturn and its myriad of rings.
The Rings of Saturn
The colorized mosaic shows the Saturn system backlit by the Sun, dated July 19, 2013, using Cassini’s visual and infrared mapping spectrometer. The team have also exaggerated the contrast of the image, which shows a snippet of 340,000 miles across, to show the subtle differences not immediately obvious.
Saturn is best known for its planetary rings, making it visually distinct. These enormous rings extend from approximately 6,600 kilometers to over 120,000 kilometers above the planet’s equator. They are primarily composed of water ice, and small amounts of amorphous carbon, with particulate that ranges wildly in size.
It can be particularly difficult to visualize these rings properly, particularly the outer F, G and E rings. Likewise, the inner D ring is difficult for astronomers to perceive when light is beaming directly upon them; this is principally because they are comprised small particles and, therefore, reflect light very poorly.
In the new infrared images, a number of the delicate rings of Saturn glow brightly, along with the dark side of the planet, a phenomenon that Matt Hedman of the University of Idaho describes:
“Looking at the Saturn system when it is backlit by the sun gives scientists a kind of inside-out view of Saturn that we don’t normally see… The parts of Saturn’s rings that are bright when you look at them from backyard telescopes on Earth are dark, and other parts that are typically dark glow brightly in this view.”
When illuminated by the Sun’s rays from behind, the rings show up in far superior detail. The researchers compare this event to fog being revealed by the headlights of an oncoming vehicle.
Ultimately, the team of astronomers were able to make the following observations:
- The B ring looks far darker in these images. Ordinarily, the B ring is the easiest to distinguish back on Earth, since it is the largest and brightest of all the massive rings circling Saturn. However, the B ring possesses huge chunks of ice, blocking out sunlight when lit from the rear.
- Meanwhile, the C ring appears somewhat bright. The material contained within the C ring is chiefly dirty water ice and, due to its very low optical density, remains fairly translucent.
- When analyzing the high contrast image, subtle qualities of the gauzy E ring were made apparent. The E ring represents the second outermost ring, with the material deriving from the south polar region of the Enceladus moon.
- The infrared images show the thermal heat radiating from the interior of Saturn. Comparatively, a normal visible-light image would only show the faintly lit face of the planet, barely illuminated by the rays of light reflected from its rings.
However, the team are still sifting through the infrared data and further results are anticipated. Phil Nicholson, one of the team members working on visual and infrared mapping spectroscopy, based at Cornell University in New York, explained that the images could provide clues as to the composition of the rings. Once the data is fully investigated, the team believes that the size of particles located within rings D, E, F and G, and how they vary with location, could be determined.
Linda Spilker, Cassini’s project scientist at NASA’s JPL, excitedly spoke of the astronomers’ upcoming work, which aims to look at seasonal changes in the rings:
“Earth looks different from season to season and Saturn does, too. We can’t wait to see how those seasonal changes affect the dance of icy particles as we continue to observe in Saturn’s rings with all of Cassini’s different ‘eyes.'”
By: James Fenner
NASA: Saturn’s Rings