When humans look up at the night sky, they naturally ask the question: How far away is that planet, or that star, or that galaxy? Distance is one of the most fundamental measurements astronomers make, ...

Early-universe probes, including the cosmic microwave background, baryon acoustic oscillations, and the inverse distance ladder, point to lower values, about 67 to 68 km/s/Mpc. The disagreement sits ...

Trying to measure the size of the universe is no easy task. We know that the universe is expanding, though the exact rate of this expansion is not yet fixed. So one method that astronomers use to tell ...

The cosmic distance ladder is the world’s longest ruler, built to measure the universe. Since the time of the ancient Greeks, scientists have been constructing a cosmic measuring tape to measure the ...