The night was as dark by this time as it would be until morning ,and what light we had ,seemed to come more from the river than the sky,as the oars in their dipping struck at a few reflected stars.
最后半句，as...stars,这里有点不理解，特别是“dipping struck” 这个地方，dipping用了现在分词，struck是strike的过去式、过去分词，为什么这样用？

原文：The night was as dark by this time as it would be until morning;and what light we had, seemed to come more from the river than the sky,as the oars in their dipping struck at a few reflected stars.　　译文：这时夜色已经黑透，看来就要这样一直黑到天明；我们仅有的一点光亮，似乎不是来自天空，而是来自河上，一桨又一桨的，搅动着那寥寥几颗倒映在水里的寒星。（王科一译）
as the oars in their dipping struck at a few reflected stars.
我觉得，dipping是动名词，搅动。in their dipping 修饰the oars，意为在他们搅动下的浆。然后前面都是过去时态，所以strike用struck。