Tuhia he haere tonu mō tēnei wāhanga - I te tau 1920 i whakaritea ia hei kaiwhakahaere o te Allegheny Observatory. I taua tau ano i uru ia ki te Whakawhitiwhiti Nui
me Harlow Shapley (e kiia ana ko te Whakawhitiwhitiwhiti a Shapley <unk> Curtis) mo te ahua o nga nebulae me nga tupuni, me te rahi o te ao. I tautoko a Curtis i te tirohanga kua whakaaetia inaianei ko etahi atu tupuni i tua atu i te Milky Way.