美国担心中国月球探测器「玉兔」轧了阿姆斯特朗的脚印，会出现这种情况吗？如何保护人类在月球上的历史遗迹？I'd personally use 'on' because a weekend is two days (or even more). 'At' is much more distinct, for just a smaller spot or shorter time, Whilst on/in are utilized for for a longer time durations