VLBI: Using Quasars to Measure the Earth

VLBI, or Very Long Baseline Interferometry, is a technique that uses multiple radio telescopes to very precisely measure the Earth's orientation. It was originally invented back in the 1960s to take better pictures of quasars, but scientists soon found out that if you threw the process in reverse, you could actually learn a lot about the Earth! Learn more about VLBI in this video!