This image was taken on August 16, 2005 and received on Earth August 16, 2005. The camera was pointing toward Hyperion at approximately 867,883 kilometres away, and the image was taken using the CL1 and UV3 filters.
This movie sequence shows Cassini's first close flyby of Hyperion, Saturn's chaotically tumbling moon. As the spacecraft whizzes past, Hyperion's unusual shape is most apparent. The jagged outlines are indicators of large impacts chipping away at Hyperion's shape.
Movie Quick Time Movie for PIA06243 Cassini's First Close Brush with Hyperion (Animation)
The low density suggests that Hyperion is mostly made of water ice, with a low rock and metal content. If the moon had significant higher density components, its implied porosity would be significantly higher than 50 percent. The dark material on the surface is therefore likely a minor component, possibly originating from impacts of dark material, as seen on Iapetus.
Hyperion's elliptical orbit and irregular shape influence its chaotic tumbling. Further, because it is in a resonance orbit with the giant moon Titan, impact debris ejected with sufficient energy does not come to rest again on Hyperion. Instead, debris is tugged gravitationally into Titan's orbit, where it impacts the large smoggy moon. This series of 25 images was taken over a period of nearly two and a half days, between June 9 and June 11, 2005, as Cassini's orbit took it close to Hyperion. Cassini will have one close, targeted flyby of Hyperion on September 26, 2005.
At the beginning of the movie Cassini was approximately 815,000 kilometres from Hyperion; at the end, the spacecraft was 327,000 kilometres distant. The closest image was acquired from a distance of 168,000 kilometres. The images were taken using the narrow-angle camera and a spectral filter sensitive to ultraviolet wavelengths centred at 338 nanometres. Image scale ranges from 5 kilometres per pixel at most distant to 1 kilometre at best. The images have been enhanced to improve the visibility of surface features.
Saturn's moon Hyperion pops into view in this stereo anaglyph (or 3D view) created from Cassini images. Images taken from slightly different viewing angles allow construction of such stereo views, which are helpful in interpreting the moon's irregular shape. Hyperion's unusual dimensions are 164 by 130 by 107 kilometres. Craters are visible on the moon's surface down to the limit of resolution in this image, about 1 kilometre per pixel. The fresh appearance of most of these craters, combined with their high spatial density, makes Hyperion look something like a sponge. The moon's spongy-looking exterior is an interesting coincidence, as Hyperion's density seems to indicate that it is porous and much of its interior is filled with voids. Dark material is concentrated in the bottoms of many craters visible here, perhaps resulting from the down slope movement of material, combined with sublimation of brighter ice.
The two images for this anaglyph were taken with the narrow-angle camera during a distant encounter with Hyperion on June 10, 2005. The views were acquired from distances ranging from about 176,000 kilometres using a spectral filter sensitive to ultraviolet wavelengths centred at 338 nanometres.
An image taken on June 10, 2005 by the Cassini spacecraft shows the Saturnine moon Hyperion. The camera was approximately 299,027 kilometres away. The image was taken using the P120 and GRN filters. This was the closest view of the moon to date.