Artist Impression Nanohertz Waves (IMAGE) National Radio Astronomy Observatory Caption The Earth is constantly jostled by low-frequency gravitational waves from supermassive black hole binaries in distant galaxies. Astrophysicists are using pulsars as a galaxy-sized detector to measure the Earth's motion from these waves. Credit B. Saxton (NRAO/AUI/NSF) Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.