Mineral Diversity at Vesta's South Pole

This image, made from data obtained by NASA's Dawn spacecraft, shows the mineral distribution in the southern hemisphere of the giant asteroid Vesta. The mineral data came from Dawn's visible and infrared mapping spectrometer, which captures different wavelengths of reflected and emitted radiation. The areas in purple have a higher proportion of diogenite minerals, and yellow areas have a higher proportion of eucrite minerals. Diogenites are silicate rocks with more magnesium than the eucrites, which are richer in iron. The mineral data lies on a mosaic obtained by Dawn's framing camera.

Credit: NASA/JPL-Caltech/UCLA/INAF/MPS/DLR/IDA

The small-scale variation and the fact that mixtures of diogenite and eucrite appear all over Vesta suggest a complex crust dominated by eucrite with intrusions of diogenitic materials. However, since diogenites appear in greater proportion at depth, the patterns suggest Vesta likely melted all the way through early in its evolution. 

The data used to create this image were obtained in August 2011, during Dawn's survey phase (on average 1,700 miles or 2,700 kilometers above the surface).

Source: 

• NASA/JPL PIA 15561, May 10, 2012