Visible/Near-Infrared Spectral Properties of MUSES C Target Asteroid 25143 Itokawa

The Japanese MUSES C mission launched the Hayabusa spacecraft last May 15, 2003, to encounter and study the near-Earth asteroid 25143 Itokawa. The spacecraft will obtain visible images through broadband filters similar to the ECAS filters, and near-infrared spectra from 0.85 - 2.1 microns. In preparation for this encounter, opportunities to study the asteroid with Earth-based telescopes have been fully leveraged. Visible and near-infrared spectral observations were made of asteroid 25143 Itokawa during several nights of March, 2001, around the last apparition. We report here on the results of extensive spectral observations made to address the questions of compositional variations across the surface of the asteroid (as determined by the rotational period and shape model); variations in phase angle (Sun-Itokawa-Earth angle) on spectral characteristics; and predictions of Itokawa observations by Hayabusa based on the spectral resolution and responsivity of the NIRS and AMICA instruments.