Data Set Overview : The LRO/LCROSS spacecraft was launched on June 18, 2009, and crashed into the Cabeus crater near the Moon's south pole on October 9, 2009. The spent upper stage, called the Centaur, impacted the moon at 11:31:19.51 UTC at -84.68 deg latitude, -48.69 deg longitude, Mean Earth frame, and the LCROSS shepherding spacecraft impacted the surface at 11:35:34 UTC.  This dataset consist of frame-transfer CCD observations of the LCROSS impact site on the Moon and ancillary supporting data made on UT October 9, 2009.  These data were acquired using the MMTO 6.5-meter telescope coupled with a Marconi Applied Technologies CCD47 camera. This is an engineering-grade CCD. Specifications for the CCD47 are available at http://www.ccd.com/pdf/ccd_47.pdf.  The CCD47 camera has a 1024 x 1024 array of 13-micron pixels, which were binned as 16 pixels x 16 pixels for the LCROSS observations. The decision to bin these pixels was made in order to trade readout rate against spatial pixel size. The camera reads out at a rate of 12.689 Hz, or 78.808 ms/frame. Of this total time, 71.269 ms is the exposure length. The remainder is the time required to read out the chip. The CCD47 camera is not cryogenically or mechanically cooled.  The observations were obtained at the MMT 6.5-meter telescope on Mt. Hopkins in Arizona. The facility is owned and operated jointly by the Smithsonian Astrophysical Observatory and the University of Arizona. This is an altitude-azimuth telescope. Adaptive optics designed and developed for the MMT incorporate an adaptive secondary mirror with incoming focal ratio of f/15. During the LCROSS observations, the f/15 adaptive optics secondary was used with the MMT natural guide star top box and the Clio camera. Inside the top box, a beamsplitter divides the incoming light into visible and infrared components, routing light of wavelengths < 950 nm to the CCD47. The CCD47 camera was positioned in the top box to receive the visible light (lower wavelength range) signal from the beamsplitter. The observations first used a neutral density filter ND2.5 followed by a filter having a central wavelength of 0.7 um with a 400-Angstrom wide passband. These observations were taken concurrently with the infrared observations taken by Clio. The infrared observations taken by Clio are described in the DATASET.CAT file for the data set EAR-L-MMTO_CLIO-2-EDR-LCROSS-V1.0.  Observing conditions were photometric with seeing measured by wavefront sensor to be 0.38 arcseconds.  The night of the LCROSS impact event was the only night we were able to take preparatory observations (other practice time allocated for observations was lost to bad weather).  Processing ----------  No processing of these images has been conducted. These images are raw data; no calibrations or corrections have been made to the images.  All CCD47 image exposures are the same exposure length as the program exposures (see above). Normal processing includes the removal of a bias frame during which no exposure is made, but the background counts generated by the readout process are subtracted from the image. Bias frame exposures are included in the data. A median filter of all or a subset of the CCD47 bias frames can be subtracted from CCD47 images of interest as part of the processing before analysis.  Data ----  The sequence of observations included observations of two A0 standard stars, HD22859 and HD43607 (http://irtfweb.ifa.hawaii.edu/) used for wavelength calibration, and the solar analogue star HD28099 (Hya 64: e.g., Farnham et al., 2000; Hardorp, 1978) for data analysis of the lunar reflectance spectra. The AO secondary system was used for these bright star observations.  About 0.33 hr prior to the LCROSS impact, the AO secondary system was triggered on a bright star near the Moon; the secondary mirror was frozen in corrected figure to remove gross aberrations caused by the atmospheric fluctuations; flat fields of the sky with the configured secondary were obtained near the Moon, and the telescope was then pointed on the Cabeus crater target area. Observations covered a time range of 8 minutes before the first impact to 36 minutes after the second impact when twilight stopped observations.  Images were taken of the Cabeus crater of the Moon where the impact was predicted to occur. The impact observations did not show any discernible effect from the impact. Quick-and-dirty image differencing immediately following the event did not show any signature of the event. Based upon the observed brightness of the impact by the LCROSS shepherding satellite, we expect that we would have been able to see the event had we not had unshadowed, illuminated portions of the lunar surface in the same field of view. The observations are described in Hastie et al. (2010).   Media/Format ------------  All data are stored in FITS format.

Review : This data set has been subjected to peer review according to Planetary Data System standards.