The Hubble constant is one of the most important numbers in cosmology because it tells us how fast the universe is expanding, which can be used to determine the age of the universe and its history. It ...

For decades, astronomers have been trying to nail down the value of the Hubble constant—a measure of how fast the universe is expanding. But some cosmologists say there’s evidence that the universe is ...

Vesto Slipher first observed that galaxies are moving away from us. Edwin Hubble later showed a relationship between galaxy distance and speed. Hubble's work relied heavily on Slipher's earlier data.

NASA has released a huge new report that astronomers are calling Hubble’s magnum opus. Analyzing 30 years of data from the famous space telescope, the new study makes the most precise measurement yet ...

New research suggests that using gravitational waves from the collisions of distant black holes could solve one of the most troubling aspects of cosmology — the rate of expansion of the universe, ...

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, ...