A New View of the Moon

A New View of the Moon

Credit: Diane Wooden, NASA Ames/Mike DiSanti, NASA GSFC/Eliot Young SwRI/Al Conrad, Jim Lyke and Terry Stickel, WMKO

This image, taken Oct. 8, 2009 with the Keck II 10-meter telescope and its guide camera, shows the LCROSS impact target position in Cabeus crater behind the mountain. Also shown and labeled are craters used as waypoints for pointing the telescope at the target position: Casatus C, Newton E and a small unnamed crater nearby (here designated as "Waypt5"). The dark circle obscuring the upper part of the lunar image is the hole in the annular guider that allows the light to reach the science instrument NIRSPEC.

A New View of the Moon

Credit: Diane Wooden (NASA Ames), Mike DiSanti (NASA GSFC), Eliot Young (SwRI), Al Conrad and Jim Lyke (WMKO) and the LCROSS Mauna Kea Spectroscopy Team

This image shows a close-up of the impact area. It was taken with the Keck II telescope and its NIRSPEC instrument and guider camera approximately 7 minutes before the first impact.

A New View of the Moon

Credit: Diane Wooden (NASA Ames), Mike DiSanti (NASA GSFC), Eliot Young (SwRI), Al Conrad, Jim Lyke and Terry Stickel (WMKO) and the LCROSS Mauna Kea Spectroscopy Team

This infrared image (taken at 1.08 micrometers) of the impact area was taken approximately 7 minutes before the first collision. It shows the Keck-NIRSPEC slit properly positioned atop a dark region. The post-impact ejecta plume is expected to have risen into this area. Further analysis will be required to establish composition of the plume by searching for molecular emissions in the spectra.

KAMUELA, HI—On Oct. 9, astronomers at the W. M. Keck Observatory used the Keck II telescope to search for water harbored in the Moon’s permanently shadowed craters.

The observations were made as part of the Observatory’s participation in NASA’s Lunar Crater Observation and Sensing Satellite, or LCROSS, mission. At 1:31 and 1:35 a.m. Hawaii Standard Time, two LCROSS impactors collided with the crater Cabeus on the South Pole of the Moon.

Diane Wooden of the NASA Ames Research Center in Moffett Field, Calif. used Keck II with its Near Infrared Echelle Spectrograph, or NIRSPEC, to analyze the resulting ejecta plume for the chemical signature of water vapor.

It is the first time that astronomers could use features on the Moon’s surface to properly position the Keck II telescope to take spectroscopic observations and images of the lunar surface. NIRSPEC’s upgraded guide camera and improved guiding software, which are part of the Observatory’s program called MAGIQ, or Multi-function Acquisition, Guiding, and Image Quality, monitoring system, made the spectroscopic observations possible and took the images.

Wooden and the other LCROSS astronomers are currently evaluating the spectroscopic data collected at Keck and the other Mauna Kea observatories for the water vapor signature. The team plans to report the results soon.

The W. M. Keck Observatory operates two 10-meter optical/infrared telescopes on the summit of Mauna Kea on the island of Hawai’i. The twin telescopes feature a suite of advanced instrumentation including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectroscopy and a world-leading laser guide star adaptive optics system. The Observatory is a scientific partnership of the California Institute of Technology, the University of California and NASA. For more information please call 808.881.3827 or visit