NASA's Cassinispacecraft has marked its final close pass of the Saturnian moonDione by capturing the rocky body in a series of stunning images asit sailed past the satellite on August, 17.Cassini had previously visited the moon five times, but hadnever before captured the moon in so high a resolution.
Dione is a relativelysmall Saturnian moon orbiting roughly 234,000 miles (377,400 km) outfrom the gas giant. With a density only 1.48 times that of liquidwater, the moon's surface is characterized by heavy cratering, withsome of the scars spanning over 60 miles (97 km) in diameter.
Cassini's latest flybytook the spacecraft to within 295 miles (474 km) of the moon on Aug. 17, capturing a series of brooding images with both its wide and narrow angle cameras. The images returned by Cassini were amere accompaniment to its primary goal of seeking clues tothe moon's interior structure as part of a gravity science experiment,the data from which will be pored over by mission scientists in themonths to come.
Two of the latestCassini shots represent the highest resolution images ever capturedof Dione's barren surface, whilst others show the moon at a distance,with Saturn and her rings looming large in the background. Regardlessof the composition, each of the shots are framed in the knowledgethat Cassini will never pass this close to Dione again, transformingthe images into a forlorn farewell from the veteran spacecraft.
"I am moved, as Iknow everyone else is, looking at these exquisite images of Dione'ssurface and crescent, and knowing that they are the last we will seeof this far-off world for a very long time to come," statesCarolyn Porco, Cassini imaging team lead at the Space ScienceInstitute, Colorado. "Right down to the last, Cassini hasfaithfully delivered another extraordinary set of riches. How luckywe have been."
Cassini may have leftDione for good, but the little probe is far from done. Prior to thecrescendo of its final year, during which the orbiter will passrepeatedy between Saturn and its iconic ring system, Cassini willpass within 30,000 miles (50,000 km) of some of the gas giant'slargest moons, and will get closer to some of the smaller irregularbodies orbiting the pale planet than ever before.
Nearly 18 years afterits launch atop a Titan IVB/ Centaur rocket, and having traveled amind-boggling distance in pursuit of its scientific objectives, theold boy still has some sights to show us.
Source: NASA JPL
