1 jan 1923 ano - Hubble discovers extragalactic objects

Descrição:

Using the fluctuations of light from variable stars in Andromeda, Hubble was able to determine the Andromeda galaxy exists outside the realms of the Milky Way at what he estimated was 900,000 light years away while in reality it exists at almost 2.5 million light years away (Messier 31) & (Biography.com).

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