Neutral sodium atoms release from the surface of the Moon induced by meteoroid impacts期刊界 All Journals 搜尽天下杂志传播学术成果专业期刊搜索期刊信息化学术搜索

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Neutral sodium atoms release from the surface of the Moon induced by meteoroid impacts

Authors:	M Bruno G Cremonese S Marchi

Institution:	Dipartimento di Scienze Mineralogiche e Petrologiche, Universitàdi Torino, Via Valperga Caluso 35, 10125 Torino, Italy;INAF Osservatorio Astronomico Padova, vic. Osservatorio 5, 35122 Padova, Italy;Dipartimento di Astronomia, Universitàdi Padova, vic. Osservatorio 6, 35122 Padova, Italy

Abstract:	In this work, we calculate the vapour and neutral Na production rates on the Moon, as due to the impacts of meteoroids in the radius range of 10^?8–0.15 m. We limit our calculations to this size range, since meteoroids with radius larger than 0.15 m have not been found to be important for the production of the exosphere in a time interval comparable with that of the observations. We have considered a new dynamical model of the flux of meteoroids at the heliocentric distance of the Moon, regarding objects in the radius range of 10^?2–0.15 m. Instead, the flux of smaller meteoroids (radius range 10^?8–10^?2 m) has been calculated using the two distributions adopted by Cintala and Love & Brownlee. The results of our model are that (i) the neutral Na production rate is ～3–4.9 × 10⁴ atoms cm^?2 s^?1 , slightly larger than the previous estimates (～2–3 × 10⁴ atoms cm^?2 s^?1) , and (ii) only about 6 per cent of neutral Na is produced by the impacts of meteoroids in the size range 10^?3–0.15 m, whereas about 94 per cent of the Na comes from the 10^?5–10^?3 m size range.

Keywords:	atmospheric effects Moon

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