<prompt> Feleletša polelwana ye e latelago: Ka 1920 ngangišano e ile ya ba gona magareng ga Harlow Shapley le Heber Curtis yo e bego e le  <response>: Great Debate, mabapi le tlhago ya Milky Way, spiral nebulae le bogolo bja legohle. E le go thekga taba ya gagwe ya gore Great Andromeda Nebula ke molalatladi wa dinaledi wa ka ntle, Curtis o ile a lemoga go tšwelela ga ditsejana tša leswiswi tšeo di swanago le maru a lerole a Milky Way, gotee le go šutha mo gogolo ga Doppler. 