Hubble, in his studies of Nebulas which turned out to be galaxies.
Edwin Hubble
No one knows the answer to that because astronomers haven't been able to explore any other galaxies besides the Milky Way.
Edwin Powell Hubble
Yes.
Yes. There are about 200 billion galaxies in the known universe.
william herschel
The Milky Way is our galaxy, the are no other galaxies within it though we are part of a local group of galaxies.
Mister Edwin Hubble did just that, before the 1920's, many astronomers thought that our galaxy included everyobject in space, in 1924 Edwin Hubble proved that other galaxies existed beyond the milky way
no we couldn't because galaxies mean the milky way and if the milky way wasn't here we wouldn't
Yes. Some examples of galaxies (which you can look up) are the: Andromeda Galaxy, the Large Magellanic cloud and the Small Magellanic Cloud.
Spiral galaxies
The Milky Way is a Galaxy.