Edwin Powell Hubble is renowned for determining that there are other galaxies in the Universe beyond the Milky Way, and for observing that the universe is expanding at a constant rate. Hubble was ...

Hubble and its fellow observatories give us an unprecedented, crystal-clear look at the far reaches of the cosmos. Explore these orbiting pioneers and learn what they've discovered. 3 min read The ...

The two keys to Edwin Hubble's breakthrough discovery were forged by others in the 1910s. The first key, the period-luminosity scale discovered by Henrietta Leavitt, allowed astronomers to ...