Crater age and hydrogen content in lunar regolith from LEND neutron data. (1st November 2018)

• Record Type: Journal Article
• Authors: Starr, Richard D.; Litvak, Maxim L.; Petro, Noah E.; Mitrofanov, Igor G.; Boynton, William V.; Chin, Gordon; Livengood, Timothy A.; McClanahan, Timothy P.; Sanin, Anton B.; Sagdeev, Roald Z.; Su, Jao J.
• Is Part Of: Planetary and space science. Volume 162(2018)
• Page Start: 105
• Page End: 112
• Publication Date: 2018-11-01
• Subjects: Lunar Reconnaissance Orbiter -- LEND -- Epithermal neutrons -- Impact craters -- Hydrogen; Space sciences -- Periodicals; Atmosphere, Upper -- Periodicals; Sciences spatiales -- Périodiques; Haute atmosphère -- Périodiques; 523
• DOI: 10.1016/j.pss.2017.08.001
• Languages: English
• ISSNs: 0032-0633

Abstract

Abstract: Analysis of Lunar Exploration Neutron Detector (LEND) neutron count rates for a large set of mid-latitude craters provides evidence for lower hydrogen content in the crater interiors compared to typical highland values. Epithermal neutron count rates for crater interiors measured by the LEND Sensor for Epithermal Neutrons (SETN) were compared to crater exteriors for 301 craters and displayed an increase in mean count rate at the ∼9-σ confidence level, consistent with a lower hydrogen content. A smaller subset of 31 craters also shows a significant increase in Optical Maturity parameter implying an immature regolith. The increase in SETN count rate for these craters is greater than the increase for the full set of craters by more than a factor of two. Highlights: SETN count rates for a large set of mid-latitude craters provides evidence for lower hydrogen content in crater interiors. Increase in mean count rate for 301 craters is significant at the ∼9-σ confidence level, implying lower hydrogen content. A smaller subset of 31 craters also shows a significant increase in OMAT implying an immature regolith. The increase in count rate for the 31 craters is greater than the increase for the full set of craters by a factor of ∼2.