The olivine at the lunar crater Copernicus as seen by Clementine NIR data

We have reduced Clementine near infrared (NIR) data in order to investigate the distribution of olivine in the crater Copernicus. Copernicus represent s a good test area for the detection of olivine-rich areas with Clementine data as olivine was unambiguously detected in the central peaks from previo us Earth-based spectroscopic observations. Clementine provides a better spa tial resolution(similar to 200 m/pixel) than Earth-based telescopic observa tions, which are limited by the atmospheric turbulence. This resolution is helpful to clarify the relationship between different lithologies and to de tect heterogeneities at small scales. NIR filters at 1100, 1250, 1500, and 2000 nm are particularly useful to discriminate between olivine and pyroxen e within the mafic minerals identified with Clementine UVVIS channels. Band ratios are presented to show the distribution of olivine-rich areas, which are detected mostly in the central peak complex. Three small areas in the northern walls are also consistent with olivine-rich materials, in agreemen t with previous studies. Nine-channels Clementine spectra confirm the overa ll heterogeneity of the crater site. This demonstrates the great potential of Clementine NIR data when integrated with UVVIS data for the detection of olivine dominated areas on the Moon. (C) 2001 Elsevier Science Ltd. All ri ghts reserved.