P53B-2123
Regional and Latitude Variability in Diurnally Modulated Neutron Flux Measured by LRO/LEND
Friday, 18 December 2015
Poster Hall (Moscone South)
Timothy A Livengood1, Igor G. Mitrofanov2, Julia Bodnarik3, William V Boynton4, Gordon Chin5, Larry G. Evans6, Karl Harshman3, Maxim L Litvak2, Timothy P McClanahan7, Roald Sagdeev8, Anton B. Sanin2, Richard D Starr9 and Jao Jang SU1, (1)University of Maryland College Park, College Park, MD, United States, (2)Space Research Institute RAS, Moscow, Russia, (3)Univ Arizona, Tucson, AZ, United States, (4)University of Arizona, Tucson, AZ, United States, (5)NASA Goddard Space Flight Center, Code 693, Greenbelt, MD, United States, (6)Computer Sciences Corporation, Stennis Space Center, MS, United States, (7)NASA Goddard Space Flight Center, Code 691, Greenbelt, MD, United States, (8)University of Maryland College Park, Physics, College Park, MD, United States, (9)Catholic University of America, Washington, DC, United States
Abstract:
Diurnal variability of epithermal neutron leakage flux from the Moon has been demonstrated at near-equatorial latitudes, combining neutron flux measurements at 30°S to 30°N from the Lunar Exploration Neutron Detector (LEND), on the polar-orbiting Lunar Reconnaissance Orbiter (LRO) spacecraft. The measured signal demonstrates a minimum at dawn and a maximum in the mid to late afternoon. The pattern is consistent with neutron flux suppression at dawn due to a maximum water concentration in the upper one meter of regolith. The present work expands on this earlier low-latitude effort by investigating specific regions of interest: the nearside Maria, the farside lunar highlands, and the farside South Pole-Aitken Basin region, as well as investigating how latitude affects the measurable diurnal variability. Investigating the possibility of regional variability tied to geologic properties of the surface may help to discriminate between interpretations for the source mechanism driving diurnal variability, temperature or variable hydrogenation/hydration of the surface.
