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.

The Hubble Space Telescope, a cornerstone of modern astronomy, has been providing breathtaking images and invaluable data for over three decades. As a collaboration between NASA and the European Space ...

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, ...