Spitzer Space Telescope - Directors Discretionary Time Proposal #289

Thermal Observations of OSIRIS target 1999 RQ36

Principal Investigator: Josh Emery 
Institution: SETI Institute / NASA Ames

Co-Investigators:
Yanga R. Ferandez, University of Central Florida 
Carl W. Hergenrother, LPL Univ. of Arizona
Dante S. Lauretta, LPL Univ. of Arizona
Michael J. Drake, LPL Univ of Arizona 

Science Category: Near-Earth Objects
Observing Modes: IRAC Mapping, IRS Staring  
Hours Approved: 5.5

Abstract: We propose to observe the near-Earth asteroid (101955) 1999 RQ36, the
target of the OSIRIS sample return mission, with IRS and IRAC.  These
observations will provide characterization of the composition,
structure, and thermophysical properties of this distinctive asteroid.
Compositionally diagnostic emissivity features measured by IRS at two
longitudes will be used to constrain the surface mineralogy and
structure (e.g., grain size, porosity).  IRS thermal flux spectra also
provide some constraint on size, albedo, and thermal inertia.  IRAC and
IRS peakup imaging photometry of 1999 RQ36 will be dominated by thermal
emission in all six bands, and will be used to map the albedo and
thermal inertia as a function of rotation, making observations at 10
different longitudes, and with higher accuracy than would be possible
with only IRS spectra.