Dee ihe ndị ọzọ dị na paragraf a - N'otu oge ahụ a na-amụ banyere mbara igwe n'ụzọ na-agbanwe agbanwe, a nọ na-enwe arụmụka na-adịte aka banyere otú mbara igwe na ụwa si malite. Onye na-enyocha mbara igwe na Mount Wilson bụ Harlow Shapley kwadoro ụdị nke mbara igwe nke mejupụtara usoro kpakpando Milky Way naanị; ebe Heber D. Curtis rụrụ ụka maka echiche ahụ na nebula ndị na-agba gburugburu bụ usoro kpakpando n'onwe ha dị ka eluigwe na ala agwaetiti. Esemokwu echiche a ruru n'ọ̀tụ̀tụ̀ ya kasị elu mgbe a haziri Nnukwu Arụmụka ahụ.
na 26 Eprel 1920 na nzukọ nke U.S. National Academy of Sciences na Washington, D.C. A doziri arụmụka ahụ mgbe Edwin Hubble chọpụtara Cepheid Variables na Andromeda Galaxy na 1923 na 1924. Ebe dị anya ha mere ka e nwee ụyọkọ kpakpando ndị yiri okirikiri n'ebe dị anya karịa Milky Way.