Aristarchus crater - Remote sensing - Encyclopedia II

In 1911, Professor Robert W. Wood used ultraviolet photography to take images of the crater area. He discovered the plateau had an anomalous appearance in the ultraviolet, and an area to the north appeared to give indications of a sulfur deposit. This colorful area is sometimes referred to as "Wood's Spot", an alternate name for the Aristarchus Plateau.

Spectra taken of this crater during the Clementine mission was used to perform mineral mapping. The data indicated that the central peak is a type of rock called anorthosite, which is a slow-cooling form of igneous rock composed of plagioclase feldspar. By contrast the outer wall is troctolite, a rock composed of equal parts plagioclase and olivine.

The Aristarchus crater region was part of a Hubble space telescope study in 2005 that was investigating the presence of oxygen-rich glassy soils in the form of the mineral ilmenite. Baseline measurements were made of the Apollo 15 and Apollo 17 landing sites, where the chemistry is known, and these were compared to Aristarchus. The Hubble Advanced Camera for Surveys was used to photograph the crater is visual and ultraviolet light. The crater was determined to have especially rich concentrations of ilmenite.

Adapted from the Wikipedia article "Remote sensing", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki/Main_Page