Edwin Hubble

Henrietta Leavitt and the Astronomical Cow Puzzle

Hubble constant, Cepheid variables, Type Ia supernovae, Edwin Hubble, Georges Lemaître, Henrietta Swain Leavitt, Adam Riess, Hubble parameter, Wendy Freedman, Vesto Slipher,

Why Scientists Are Confused About How Fast the Universe Is Expanding

In the constellation Cassiopeia, 7,100 lightyears away, a start 45-times as heavy as our Sun is blowing out superhot winds of gas travelling at 6.4 million km/hr. These winds push against the much cooler blanket of interstellar gas, bunching them up along the surface of a giant bubble over seven lightyears across. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

10 Iconic Images to Recall 26 Years of the Hubble Space Telescope