Saturn's diminutive moon, Mimas, poses as the Death Star - the planet-destroying space station from the movie Star Wars - in an image recently captured by NASA's Cassini spacecraft.
A giant crater 138 kilometres across dominates the landscape of Mimas and represents almost one-third of the moon's diameter.
Scientists first noticed Mimas's resemblance to the Death Star when the twin Voyager spacecraft flew past Saturn in 1980 and 1981. The second film in the movie series - The Empire Strikes Back - had just hit movie theatres, recalls Cassini deputy project scientist Linda Spilker.
Now, Cassini has taken an even better image than those from the Voyager probes with its narrow-angle camera. It snapped the photo on 16 January 2005 from 213,000 km away at a resolution of 1.3 km per pixel.
Like the Death Star, Mimas has found itself on the receiving end of some heavy fire. The crater was probably caused by an enormous asteroid impact. But the moon only just survived - if the asteroid had been any bigger or moving much faster, it probably would have split the moon in two.
Most of the craters on Mimas are named after characters in Camelot. But the biggest crater was named after Sir William Herschel, the scientist who discovered Mimas. "Herschel's the oddball crater that doesn't really fit in," Spilker told New Scientist.
The peak in the middle of Herschel crater was also formed by the impact, when pulverised or molten rock rebounded upwards like a droplet of water splashing up from a pool of water.
NASA's Jet Propulsion Laboratory in Pasadena, California, US, released the image on Thursday.
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18:53 05 September 2008
