利用业余天文观测验证与探究月球天平动现象

Utilizing amateur astronomical observations to verify and investigate the phenomenon of lunar libration.

摘要

月球天平动是月球绕地球运行过程中表现出的复杂摆动现象，它使我们能够观察到约59%的月面，而非理论上的50%。本研究旨在通过设计系统的业余天文观测方案，对月球天平动现象进行定量验证与探究。我们使用学校天文社的入门级专业设备（口径150mm反射式望远镜及行星相机），在2023年9月至2024年2月期间，选择每月农历十八至廿三的固定时间段，对月球边缘三个特征标志点（环形山“哥白尼”、“第谷”及危海边缘）进行持续拍摄与测量。通过图像处理软件叠加分析，记录并计算这些特征点在月面经纬度方向上的视位移变化。观测数据清晰地揭示了月球在经度和纬度方向的周期性摆动，与理论预测的周期和幅度基本吻合。本研究不仅直观验证了这一经典天文学现象，更通过实践深化了对月球轨道力学复杂性的理解，体现了业余天文观测在基础科学研究中的独特价值。

Abstract

Lunar libration is a phenomenon of apparent oscillation caused by discrepancies between the Moon’s orbital and rotational parameters as it revolves around Earth, enabling humans to observe approximately 59% of the lunar surface—exceeding the theoretically expected 50%. This study designed a systematic amateur astronomical observation program to quantitatively verify and investigate this phenomenon. Using a 150mm aperture reflecting telescope and planetary camera from the school astronomy club, continuous imaging and measurements were conducted from September 2024 to February 2025, during fixed time periods each month from the 18th to the 23rd of the lunar calendar, targeting three characteristic lunar limb features: the Copernicus crater, Tycho crater, and the edge of Mare Crisium. Through image stacking and coordinate analysis, apparent displacement sequences of these landmarks along the lunar longitudinal and latitudinal directions were extracted. The results show that the Moon exhibits significant periodic oscillations in both longitude and latitude, with periods and amplitudes largely consistent with theoretical predictions. This work not only successfully confirms the existence of libration but also deepens understanding of the complex dynamics of the Moon’s orbit, highlighting the potential value of amateur astronomical observations in basic scientific education and research.

关键词

月球天平动 / 业余天文观测 / 月面测量 / 轨道力学 / 天文探究

Key words

Lunar libration / amateur astronomical observation / lunar surface measurement / orbital mechanics / astronomical investigation

参考文献

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[2] 如何精确测量地球与月球之间的距离. 周书华.物理, 2025(08)

[3] 天文观测和物理模型不同角度对行星冲日的分析——2023年1月浙江省物理选考卷第10题分析. 肖飞燕.物理教师, 2023(05)