The most precise measurement yet of how fast the Universe is expanding shows we have a real and serious problem on our hands.

A difference of a few kilometers per second might not sound like much. In cosmology, it has become one of the field’s most stubborn problems. An international team of astronomers has now delivered one ...

From the stars in our backyard to galaxies billions of light-years away, astronomers use a 'cosmic distance ladder' of methods to map the universe. Now, a global team has unified Hubble constant ...

Artist’s interpretation of the cosmic distance ladder — a succession of overlapping methods used to measure distances across the Universe, where each rung of the ladder provides information that can ...