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Illumination Conditions of the Lunar Polar Regions Using LOLA TopographyWe use high-resolution altimetry data obtained by the Lunar Orbiter Laser Altimeter instrument onboard the Lunar Reconnaissance Orbiter to characterize present illumination conditions in the polar regions of the Moon. Compared to previous studies, both the spatial and temporal extent of the simulations are increased significantly, as well as the coverage (fill ratio) of the topographic maps used, thanks to the 28 Hz firing rate of the five-beam instrument. We determine the horizon elevation in a number of directions based on 240 m-resolution polar digital elevation models reaching down to 75 latitude. The illumination of both polar regions extending to 80 can be calculated for any geometry from those horizon 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). We extended our direct illumination model to account for singly-scattered light, and found that every PSR does receive some amount of scattered light during the year. We conducted simulations over long periods (several 18.6-years lunar precession cycles) with a high temporal resolution (6 h), and identified the most illuminated locations in the vicinity of both poles. Because of the importance of those sites for exploration and engineering considerations, we characterized their illumination more precisely over the near future. Every year, a location near the Shackleton crater rim in the south polar region is sunlit continuously for 240 days, and its longest continuous period in total darkness is about 1.5 days. For some locations small height gains ( 10 m) can dramatically improve their average illumination and reduce the night duration, rendering some of those particularly attractive energy-wise as possible sites for near-continuous sources of solar power.
Document ID
20120010094
Document Type
Reprint (Version printed in journal)
Authors
Mazarico, E. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Neumann, G. A. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Smith, D. E. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Zuber, M. T. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Torrence, M. H. (Stinger Ghaffarian Technologies, Inc. (SGT, Inc.) Greenbelt, MD, United States)
Date Acquired
August 25, 2013
Publication Date
February 1, 2011
Publication Information
Publication: Icarus
Volume: 211
Issue: 2
Subject Category
Lunar and Planetary Science and Exploration
Report/Patent Number
GSFC.JA.00103.2012
GSFC-E-DAA-TN77507
Funding Number(s)
CONTRACT_GRANT: 80NSSC19K1277
Distribution Limits
Public
Copyright
Other