Ganymede's Nergal Crater
Two impact craters surrounded by an unusual ejecta blanket dominate this high-resolution image of the surface of Jupiter's moon Ganymede. NASA's Galileo spacecraft photographed this region as it passed Ganymede during its second orbit through the jovian system. North is to the top of the picture, and the Sun illuminates the surface from the southeast. Nergal, the larger crater, is about 8 kilometers in diameter, while the smaller (unnamed) crater to its west is 3 kilometers across. The craters are situated in a region of bright grooved terrain named Byblus Sulcus, located in the northern part of Marius Regio at 390N latitude and 2010W longitude. The distinctive ejecta blanket that surrounds them is darker nearer the craters and brighter further away. The inner region of the ejecta is characterized by a lobate appearance indicative of the flow of a liquid (or slushy) substance over the surface. The flow was probably icy surface material melted by the energy released during the impact that formed the crater.
Date: 6 Sep 1996
The picture covers an area about 48 by 34 kilometers across at a resolution of 86 meters per picture element. The image was taken on September 6, 1996, by the Solid-State Imaging System onboard the Galileo spacecraft.
Image Credit: Brown University
Credit: Lunar and Planetary Institute