The Cat's Eye Nebula is located 4,400 light-years away in the constellation Draco.

J.-C. Cuillandre & E. Bertin (CEA Paris-Saclay), Z. Tsvetanov This new NASA/ESA Hubble Space Telescope image features one of ...

The universe’s expansion rate was supposed to be a solved problem, yet the latest high precision map of the early cosmos has pushed one of modern astronomy’s sharpest conflicts back to center stage.

Astronomers have long known the universe is expanding—but exactly how fast remains one of the biggest mysteries in cosmology.

Scientists are testing a novel way to measure cosmic expansion using time delays in gravitationally lensed quasars. Their results match “local” measurements but clash with early-universe estimates, ...