Dark energy is still a mystery, but powerful new telescopes are set to uncover clues. With NASA and ESA leading the charge, ...

A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the ...

The two people whose shoulders Hubble stood on the most, though, were Henrietta Swan Leavitt and Harlow Shapley. Leavitt worked at Harvard College Observatory as a "computer" who would analyze ...

There are no tape-measures in space, but by the early 20th century Henrietta Swan Leavitt had discovered that the pulsation period of Cepheid variables is directly tied to their luminosity.

Hubble leveraged a discovery made by Henrietta Swan Leavitt 10 years earlier. She worked at the Harvard College Observatory as a “human computer,” laboriously measuring the positions and ...