December 25, 2015

"NASA's Dawn spacecraft, cruising in its lowest and final orbit at dwarf planet Ceres, has delivered the first images from its best-ever viewpoint."

NASA The new images showcase details of the cratered and fractured surface. 3-D versions of two of these views are also available.

'Dawn took these images of the southern hemisphere of Ceres on Dec. 10, at an approximate altitude of 240 miles (385 kilometers), which is its lowest-ever orbital altitude. Dawn will remain at this altitude for the rest of its mission, and indefinitely afterward. The resolution of the new images is about 120 feet (35 meters) per pixel.

'Among the striking views is a chain of craters called Gerber Catena, located just west of the large crater Urvara. Troughs are common on larger planetary bodies, caused by contraction, impact stresses and the loading of the crust by large mountains -- Olympus Mons on Mars is one example. The fracturing found all across Ceres' surface indicates that similar processes may have occurred there, despite its smaller size (the average diameter of Ceres is 584 miles, or 940 kilometers). Many of the troughs and grooves on Ceres were likely formed as a result of impacts, but some appear to be tectonic, reflecting internal stresses that broke the crust.

'"Why they are so prominent is not yet understood, but they are probably related to the complex crustal structure of Ceres," said Paul Schenk, a Dawn science team member at the Lunar and Planetary Institute, Houston.'

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