Image of the Week: Saturn’s strange, misshapen moon.
5 Mar 2012
This stunning view of Saturn's moon Hyperion reveals in crisp detail the strange moon's surface.
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The sponge like surface of Saturn’s moon Hyperion, as viewed by Cassini.
Credit: NASA/JPL/Space Science Institute.
The Cassini-Huygens missions was launched in 1997, combining Cassini an orbiting craft and Huygens a probe on the surface of Saturn’s largest moon, Titan. Since entering orbit in 2004 Cassini has transformed our understanding of Saturn and made some amazing discoveries about the nature and geology of its 53 moons.
Cassini scientists think that Hyperion's unusual, sponge-like appearance may be due to its unusually low density for such a large object, giving it weak surface gravity and high porosity. These characteristics help preserve the original shapes of Hyperion's craters. On Hyperion impactors have tended to compress the surface material, rather than blasting it out. There is little material to coat the surface to create a smoother appearance. Instead any material blasted out is likely to escape because of the moons weak gravity and correspondingly low escape velocity.
The natural reddish tint of Hyperion was toned down for this false colour image. The other hues were enhanced in order to make more subtle colour variations across the surface more apparent. Differences in colour could represent differences in the composition of surface materials. Inspecting the moon in this way gives scientists a better idea of its geology.
This view was obtained during Cassini's very close flyby on 26 September 2005 using infrared, green and ultraviolet spectral filters were combined to create the image. The images were taken with the narrow-angle camera at a distance of approximately 62,000 kilometres (38,500 miles) from Hyperion and at a sun-Hyperion-spacecraft, or phase, angle of 52 degrees. The image scale is 362 meters (1,200 feet) per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. UK universities and industry played a vital role in the design, engineering and science of the mission.