In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they ...

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 ...

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 ...

A newly identified Kuiper Belt trio, possibly only the second of its kind, could provide strong evidence that these distant ...

Photo: Andromeda nebula plate with Hubble's handwritten circle around the variable star he discovered In 1919 American astronomer Edwin Hubble began work at the Mount Wilson Observatory in ...

An ambitious new survey by the Hubble Space Telescope offers the first bird's-eye view of all known dwarf galaxies orbiting ...

Hubble’s work opened the door to the study ... In 1610, astronomer Galileo Galilei used the newly invented telescope to show that the Milky Way was composed of a huge number of faint stars.

Hubble's work opened the door to the study of ... In 1610, astronomer Galileo Galilei used the newly invented telescope to show that the Milky Way was composed of a huge number of faint stars.

Hubble’s work opened the door to the study ... In 1610, astronomer Galileo Galilei used the newly invented telescope to show that the Milky Way was composed of a huge number of faint stars.