Galileo image of asteroid 951 Gaspra.  This image is a combination of images taken with the violet, green and near-IR filters at a resolution of about 163 m/pixel overlain on a 54 m/pixel resolution clear filter image.  The colors are highly exaggerated to bring out subtle differences in surface properties.  Bluish regions represent fresher rock, while reddish regions are composed of regolith materials.  Gaspra is an irregularly shaped body about 19 by 12 by 11 km.  The illuminated portion in this image is about 18 km from lower left to upper right .  The sun is shining from the right.  Photo courtesy of NASA. (Galileo, P-40450c)