在列表中检索

1
1

2
共检索到 2

Lunar regolith samples contain fragments of endogenic rocks and exogenous meteorites. We report the first discovery of a chondrule fragment preserved in Chang'e-5 (CE-5) regolith samples. Forsterite and enstatite phenocrysts have extremely high Mg# (> 99) and high Mn/Fe ratios in this chondrule fragment. Its glass mesostasis is heterogeneous and contains hydrogen and carbon, as indicated by Raman peaks. The mineral assemblage, chemical composition, and oxygen isotope anomaly of this fragment are similar to those of type-I chondrules from carbonaceous chondrites. This fragment and other chondritic relics with 3.4 Ga. This contrast suggests that there may have been a change of impactors to the Earth-Moon system during the Imbrian period. Furthermore, this CE-5 chondrule fragment is a direct record of volatile addition to the Moon's surface from meteorites during the Eratosthenian period.

期刊论文 2025-03-15 DOI: 10.1016/j.icarus.2025.116454 ISSN: 0019-1035

Dust particles exist everywhere in interplanetary space and they evolve dynamically after their origination from the sources like Asteroid belt, Kuiper belt, comets or space debris left during the formation of solar system. These micrometeorites encounter the inner planets, while they spiral-in towards the Sun. From whichever come to Earth, many particles are ablated in the Earth's atmosphere and leave the metallic ions behind. In case of Moon, all such particles can reach the surface without ablation owing to the absence of atmosphere. Due to the impact of hypervelocity dust particles on lunar surface, ejecta come out in the lunar environment. In some cases, the ejecta velocity could be larger than the escape velocity and particles may be able to escape from Moon. Further, the escaping ejecta may carry water ice (volatiles), whenever incoming projectiles hit the surface in polar region with the water ice present. In this paper, we have computed the ejecta parameters and estimated the possible escape of volatiles from Moon, using Galileo observations of the dust particles near Moon. Considering the incident angle distribution, the upper limit of regolith escape rate is found to be similar to 2.218 x 10(-4) [1.662 x 10(-4), 10.232 x 10(-4)] kg/s. Similarly, the upper limit of water ice escape rate is found to be similar to 1.988 x 10(-7) [1.562 x 10(-7), 7.567 x 10(-7)] kg/s. On one side, Moon is found to be gradually becoming heavier due to its one order higher incoming dust particles than those escaping from it. While on the other side, Moon could be depleted of water ice (volatiles) resources over a period of time, because of the escape due to micrometeorite impact. The results presented here could be useful to understand the dust and volatile escape from Moon.

期刊论文 2020-03-01 DOI: 10.1016/j.icarus.2019.113510 ISSN: 0019-1035
  • 首页
  • 1
  • 末页
  • 跳转
当前展示1-2条  共2条,1页