Resources Worm-like Markings on Vesta's Surface Photojournal: PIA14696 Source: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA Published: September 9, 2011 This image from NASA's Dawn spacecraft shows dark material at impact craters, up to 12.5 miles-wide (20 kilometer-wide) and sets of worm-like tracks in the north-south direction. ENLARGE