Modeling the LCROSS Impact Site

A two-ton Atlas Centaur rocket body, part of the Lunar Crater Observation and Sensing Satellite (LCROSS), struck the floor of Cabeus crater, near the south pole of the moon, at 11:31 UT on October 9, 2009. The purpose of the crash was to create a plume of debris that could be examined for the presence of water and other chemicals in the lunar regolith. The effects of the impact were captured by sensors onboard a shepherding satellite travelling four minutes behind the Centaur. They were also watched by Earth-based observatories and several Earth-orbiting satellites, including the Hubble Space Telescope.

The images here were created in the weeks prior to the impact. They visualize the viewing angle, terrain, and shadows around the target crater at the time of the impact. Astronomers in New Mexico, Arizona, California, and Hawaii used them as visual reference while guiding their telescopes. LCROSS project scientists also used these and similar images to evaluate a number of potential impact locations.

Using the Jet Propulsion Laboratory's DE421 ephemeris and early terrain data from Lunar Reconnaissance Orbiter's laser altimeter, the artist was able to accurately depict the sunlight direction, shadows, moon orientation, terrain, and field of view for several representative observing locations on the Earth.

See http://www.nasa.gov/centers/goddard/news/topstory/2009/svs_lcross.html