<prompt> Qedela umusho olandelayo: Ngo-1920 kwaba nengxoxo-mpikiswano phakathi kukaHarlow Shapley noHeber Curtis umholi we-  <response>: Inkulumompikiswano Enkulu, ephathelene nemvelo yeMilky Way, i-spiral nebulae, nobukhulu bendawo yonke. Ukuze asekele isimangalo sakhe sokuthi i-Great Andromeda Nebula iyinkanyezi engaphandle, uCurtis waphawula ukubonakala kwemizila emnyama efana namafu othuli eMilky Way, kanye nokushintsha okukhulu kweDoppler. 