Lunar Dust Fountain Observed Near Twilight Craters. Issue 23 (24th November 2020)

• Record Type: Journal Article
• Authors: Xie, Lianghai; Zhang, Xiaoping; Li, Lei; Zhou, Bin; Zhang, Yiteng; Yan, Qi; Feng, Yongyong; Guo, Dawei; Yu, Shuoran
• Is Part Of: Geophysical research letters. Volume 47:Issue 23(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-11-24
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2020GL089593
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Lunar horizon glows observed by the Apollo missions suggested a dense dust exosphere near the lunar terminator. But later missions failed to see such a high‐density dust exosphere. Why the Apollo missions could observe so large number of dust grains remains a mystery. For the first time, we report five dust enhancement events observed by the Lunar Dust Experiment on board Lunar Atmosphere and Dust Environment Explorer mission, which happen near a twilight crater with dust densities comparable to the Apollo measurements. Moreover, the dust densities are larger on the downstream side of the crater and favor a higher solar wind temperature, consistent with an electrostatic dust lofting from the negatively charged crater floor. We also check the Apollo observations and find similar twilight craters, suggesting that the so‐called dust exosphere is not a global phenomenon but just a local electrified dust fountain near twilight craters. Plain Language Summary: With in situ dust measurements, we find that a shadowed crater near the terminator can dramatically change the surface electrical environment and bring a dense dust cloud surrounding the crater, which should be carefully assessed by engineers for future lunar explorations. Moreover, our findings have the general implications in studying the dust environment near large topographic features (mountains and deep craters) of all kinds of airless bodies. Key Points: We find five dust enhancements events near twilight craters, with the in situ dust measurements of the LADEE mission The dust enhancement events can be caused by an electrostatic dust lofting from the leeward wall of a twilight crater The lunar horizon glow observed in the Apollo missions can be also related to a twilight crater