Skip to main content
Sodium Atoms in the Lunar Exotail: Observed Velocity and Spatial Distributions
  • Michael R. Line, California Institute of Technology
  • E. J. Mierkiewicz, University of Wisconsin - Madison
  • R. J. Oliversen, NASA Goddard Space Flight Center
  • J. K. Wilson, University of New Hampshire
  • L. M. Haffner, University of Wisconsin
  • F. L. Roesler, University of Wisconsin
Document Type
Publication/Presentation Date

The lunar sodium tail extends long distances due to radiation pressure on sodium atoms in the lunar exosphere. Our earlier observations measured the average radial velocity of sodium atoms moving down the lunar tail beyond Earth (i.e., near the anti-lunar point) to be ∼12.5. km/s. Here we use the Wisconsin H-alpha Mapper to obtain the first kinematically resolved maps of the intensity and velocity distribution of this emission over a 15° × 15 ° region on the sky near the anti-lunar point. We present both spatially and spectrally resolved observations obtained over four nights bracketing new Moon in October 2007. The spatial distribution of the sodium atoms is elongated along the ecliptic with the location of the peak intensity drifting 3° east along the ecliptic per night. Preliminary modeling results suggest the spatial and velocity distributions in the sodium exotail are sensitive to the near surface lunar sodium velocity distribution. Future observations of this sort along with detailed modeling offer new opportunities to describe the time history of lunar surface sputtering over several days.

Additional Information

© 2012 Elsevier Inc.

Dr. Mierkiewicz was not affiliated with Embry-Riddle Aeronautical University when this paper was published.

Citation Information
Michael R. Line, E. J. Mierkiewicz, R. J. Oliversen, J. K. Wilson, et al.. "Sodium Atoms in the Lunar Exotail: Observed Velocity and Spatial Distributions" Icarus Vol. 219 Iss. 2 (2012) p. 609 - 617
Available at: