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Presentation
Line Profile Measurements of the Lunar Exospheric Sodium
5th NASA Lunar Science Forum (2012)
  • Ronald J. Oliversen, Goddard Space Flight Center (NASA)
  • Edwin J. Mierkiewicz, University of Wisconsin - Madison
  • Michael J. Line, California Institute of Technology
  • Fred L. Roesler, University of Wisconsin - Madison
  • Olivia L. Lupie, Goddard Space Flight Center (NASA)
Abstract
We report ongoing results of a program to measure the lunar sodium exospheric line profile from near the lunar limb out to two lunar radii (approx 3500 km). These observations are conducted from the National Solar Observatory McMath-Pierce telescope using a dual-etalon Fabry-Perot spectrometer with a resolving power of 180,600 (1.7 km/s) to measure line widths and velocity shifts of the Na D2 (5889 950 A) emission line in equatorial and polar regions at different lunar phases. The typical field of view (FOV) is 3 arcmin (approx 360 km) with an occasional smaller 1 arcmin FOV used right at the limb edge. The first data were obtained from full Moon to 3 days following full Moon (waning phase) in March 2009 as part of a demonstration run aimed at establishing techniques for a thorough study of temperatures and velocity variations in the lunar sodium exosphere. These data indicate velocity displacements from different locations off the lunar limb range between 150 and 600 m/s from the lunar rest velocity with a precision of +/- 20 to +/- 50 m/s depending on brightness. The measured Doppler line widths for observations within 10.5 arcmin of the east and south lunar limbs for observations between 5 deg and 40 deg lunar phase imply temperatures ranging decreasing from 3250 +/- 260K to 1175 +/- 150K. Additional data is now being collected on a quarterly basis since March 2011 and preliminary results will be reported.
Keywords
  • Lunar exosphere,
  • Moon
Publication Date
July, 2012
Location
Moffett Field, CA
Comments
GSFC.ABS.7441.2012
Citation Information
Ronald J. Oliversen, Edwin J. Mierkiewicz, Michael J. Line, Fred L. Roesler, et al.. "Line Profile Measurements of the Lunar Exospheric Sodium" 5th NASA Lunar Science Forum (2012)
Available at: http://works.bepress.com/edwin_mierkiewicz/80/