Multi-Wavelength Observations and Analysis of Asteroid 2100 Ra-Shalom

Commonwealth University Of Pennsylvania, Bloomsburg PA

Investigators

Abstract

AST 0307092 Shepard Dr. Michael Shepard, at Bloomsburg University of Pennsylvania, and Dr. Beth Clark, at Ithaca College, will conduct a multi-wavelength campaign of observation and analysis of asteroid 2100 Ra-Shalom during its August 2003 close approach. Ra-Shalom is of interest for several reasons. (1) Ra-Shalom is one of the largest members of the Aten near-Earth population, a group that is poorly characterized. (2) Ra-Shalom is one of a handful of asteroids that appear to have little or no surface regolith, suggested by very high values of surface thermal inertia. (3) Spectral data gathered to-date strongly suggest Ra-Shalom to be a K-class asteroid, similar to members of the Eos family, and a good spectral match to CV3 meteorites. (4) Ra-Shalom has a relatively low delta-V, making it a good candidate for future spacecraft missions. August 2003 offers the best opportunity to study Ra-Shalom for the next two decades. These investigators will make the following near-simultaneous observations of Ra-Shalom over one complete rotation so that all sides are observed: (1) 12.6-cm radar imaging at ~50 m/pixel resolution or better (Arecibo), (2) Near Infrared (NIR, 0.8 - 3.5 micron) observations (Infrared Telescope Facility), (3) Ultra-Violet/Visible (0.3-0.9 micron) observations (Kitt Peak/McDonald), and (4) Thermal Infrared (TIR, 8-14 micron) observations (Palomar). The observations are designed to image all of Ra-Shalom in multi-wavelengths to address the following questions: (1) What is the shape and physical structure of Ra-Shalom? (2) What large scale surface features can be discerned? (3) Are there rotational phase spectral heterogeneities? If so, can surface features be correlated with these variations? (4) Do spectral variations (if existent) suggest compositional or textural (e.g. grain size) variations? (5) Can a water absorption feature be identified? (6) Can we confirm or refute a lack of regolith? (7) If the K-classification is confirmed, can a link be made between this asteroid and the Eos main-belt population? (8) Can a reasonable case be made that this near-Earth asteroid (NEA) is the source of any meteorites in our collections? The broader impacts of this work can be summarized as follows. A detailed characterization of this asteroid provides society with information that will be of use to: (1) Evaluate the threat of asteroid impacts with the Earth, (2) Evaluate the potential resources available in the near Earth asteroid population, and (3) Increase understanding of the primitive building blocks of the Solar System. ***