  The Lunar CRater Observation and Sensing Satellite (LCROSS) observed the
distant Earth on three occasions in 2009. These data span a range of phase
angles, including a rare crescent phase view. For each epoch, the satellite
acquired near-infrared and mid-infrared full-disk images, and partial-disk
spectra at 0.26-0.65 microns (R~500) and 1.17-2.48 microns (R~50). Spectra show
strong absorption features due to water vapor and ozone, which is a
biosignature gas. We perform a significant recalibration of the UV-visible
spectra and provide the first comparison of high-resolution visible Earth
spectra to the NASA Astrobiology Institute's Virtual Planetary Laboratory
three-dimensional spectral Earth model. We find good agreement with the
observations, reproducing the absolute brightness and dynamic range at all
wavelengths for all observation epochs, thus validating the model to within the
~10% data calibration uncertainty. Data-model comparisons reveal a strong ocean
glint signature in the crescent phase dataset, which is well matched by our
model predictions throughout the observed wavelength range. This provides the
first observational test of a technique that could be used to determine
exoplanet habitability from disk-integrated observations at visible and
near-infrared wavelengths, where the glint signal is strongest. We examine the
detection of the ozone 255 nm Hartley and 400-700 nm Chappuis bands. While the
Hartley band is the strongest ozone feature in Earth's spectrum, false
positives for its detection could exist. Finally, we discuss the implications
of these findings for future exoplanet characterization missions.
