NASA Developing Plans to Capture Lunar Impacts
A team of scientists, led by Diane Wooden of NASA’s Ames Research Center has created a detailed mosaic image of the moon’s south pole to help observe the dual impacts of the Lunar CRater Observation and Sensing Satellite (LCROSS) mission.
Scientists created the composite image using observation data collected early in Nov. 2008 using NASA’s Infrared Telescope Facility (IRTF) located atop Mauna Kea on the Big Island of Hawaii.
Wooden and her team are developing procedures to allow the IRTF and other telescopes involved in the LCROSS Observation Campaign to precisely target and observe the short-duration LCROSS impact flashes and debris plumes.
Unlike observing a distant star or nebulae, observing a specific event on the moon poses significant challenges for large telescopes like the IRTF. The moon is extremely bright and moves rapidly compared to the background stars. For a large telescope to observe the moon, numerous procedures have to be implemented including the installation of special filters to block excess light and positioning of the telescope to track the target's location.
The final mosaic image is composed of 699 images taken on Nov. 7, 2008 UT. Wooden and her colleagues Michael Kelly (UCF), Paul Lucey (HIGP) and John Rayner (UH/IFA), obtained the images using the near-IR SpeX spectrometer and imaging instrument on the IRTF. Due to high cirrus clouds, some, but not all frames are over exposed. A neutral density filter that transmits only one percent has been installed, together with a narrow band filter to mitigate the overexposure for the next three half-night observing runs on Dec. 6-8, 2008.
The LCROSS impact ejecta plumes will rise above rim of a permanently shadowed crater into sunlight. The ejecta plumes evolve sideways like an upside down lampshade, for up to a couple of minutes. The extremely short duration of the LCROSS impacts, is the motivation for the pre-impact pointing, guiding, and data acquisition exercises Wooden and her team are conducting in Hawaii.
On the night of lunar impacts, a similar mosaic will be obtained at the IRTF and shared with other professional astronomers along with offset coordinates from identified craters. The mosaic will enable astronomers to confirm their pointing position to the LCROSS impact sites using the exact lighting and libration, the wobble of the moon on its axis, on that day.
The LCROSS Observation Campaign was developed to solicit the help of amateur and professional astronomers to maximize the data collected from this unique mission designed to search for possible water ice in permanently shadowed craters at the moon’s poles. The LCROSS mission launch is scheduled for a late April 2009 launch with the impacts scheduled for late summer.
For detailed specifics on the Nov. 7, 2008 mosaic image and information about the next Dec. 6-8, 2008 observations, visit:
Image and December Observation Run Specifications