Illumination Conditions of the Lunar Polar Regions Using LOLA Topography ⇑ E
Icarus 211 (2011) 1066–1081 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Illumination conditions of the lunar polar regions using LOLA topography ⇑ E. Mazarico a,b, ,1, G.A. Neumann a, D.E. Smith a,b, M.T. Zuber b, M.H. Torrence a,c a NASA Goddard Space Flight Center, Planetary Geodynamics Laboratory, Greenbelt, MD 20771, United States b Massachusetts Institute of Technology, Department of Earth, Atmospheric and Planetary Sciences, Cambridge, MA 02139, United States c Stinger Ghaffarian Technologies, Inc., Greenbelt, MD 20770, United States article info abstract Article history: We use high-resolution altimetry data obtained by the Lunar Orbiter Laser Altimeter instrument onboard Received 21 May 2010 the Lunar Reconnaissance Orbiter to characterize present illumination conditions in the polar regions of Revised 24 October 2010 the Moon. Compared to previous studies, both the spatial and temporal extent of the simulations are Accepted 29 October 2010 increased significantly, as well as the coverage (fill ratio) of the topographic maps used, thanks to the Available online 12 November 2010 28 Hz firing rate of the five-beam instrument. We determine the horizon elevation in a number of direc- tions based on 240 m-resolution polar digital elevation models reaching down to 75° latitude. The illu- Keyword: mination of both polar regions extending to 80° can be calculated for any geometry from those horizon Moon longitudinal profiles. We validated our modeling with recent Lunar Reconnaissance Orbiter Wide-Angle Camera images. We assessed the extent of permanently shadowed regions (PSRs, defined as areas that never receive direct solar illumination), and obtained total areas generally larger than previous studies (12,866 and 16,055 km2, in the north and south respectively).
[Show full text]