The observation that finally unlocked this mystery was made just a few years later when Edwin Hubble and Milton Humason observed the great spiral nebula M31 in Andromeda, using what was at the time the largest telescope in the world.

仅仅几年之后，埃德温·哈勃和弥尔顿·胡马森就用当时世界上最大的望远镜观测了仙女座的巨大螺旋星云 M31，最终解开了这个谜团。