Mosaic of the four high-resolution images C2684533, C2684535, C2684537 and C2684539 of Ariel,
taken by Voyager 2 on January 24, 1986, at a distance of about 130,000 kilometers.
Ariel is about 1,200 km in diameter.
The most notable features on this moon are the interconnected rift valleys that run across the highly pitted terrain. Some of the valleys are up to 10 km deep. They have formed as a result of expansion and stretching of Ariel’s crust.
Two of the Voyager images covering the terminator on the right are somewhat blurred due to the spacecraft’s motion and the longer exposure times of the camera. This could not be completely corrected during image processing.
Image Credit: NASA/JPL/Mosaic by astroarts.orgoff
On July 9, 2009, was the thirtieth anniversary of the flyby of the Voyager 2 probe past Jupiter.
The picture shown here, taken by Voyager 2 from a distance of 246,000 kilometers, was the first close look ever obtained of Jupiter’s satellite, Europa.
The linear crack-like features had been seen from a much greater distance by Voyager 1, but this image provides a resolution of about four kilometers. The complicated linear features appear even more like cracks or huge fractures in this image. Also seen are somewhat darker mottled regions which appear to have a slightly pitted appearance, due to small scale craters.
No large craters (more than five kilometers in diameter) are easily identifiable in the Europa photographs to date, suggesting that this satellite has a young surface.
Various models for Europa’s structure were tested during analysis of this image, including the possibility that the surface is a thin ice crust overlying water or softer ice and that the fracture systems seen are breaks in that crust. Resurfacing mechanisms such as production of fresh ice or snow along the cracks and cold glacier-like flows were considered as possibilities for removing evidence of impact events.
Photo-ID: JPL P-21758; Raw Image Name: A79-7087; Date: July 9, 1979.
The image here is a scan from a print of the original data, so some image quality is lost.
Image Credit: NASA Ames Research Center/astroarts.orgoff