In the 1920s in California,
astronomer Edwin Hubble
observed distant galaxies using an extremely
powerful telescope. He made two mind-boggling discoveries.
Hubble figured out that the Milky Way isnt the only galaxy.
He realized that faint, cloud-like objects in the night sky are
actually other galaxies far, far away. The Milky Way is just one
of billions of galaxies.
Hubble discovered that the galaxies are constantly moving away from
each other. In other words, the universe is expanding. The biggest thing that
we know about is getting bigger all the time.
few years later,
Belgian astronomer Georges Lemaître used Hubbles amazing
discoveries to suggest an answer to a big astronomy question: How
did the universe