Shepherding Panets Illustrated (IMAGE) National Radio Astronomy Observatory Caption Particles in dust ring are kept inside the ring by gravitational interaction with planets. Faster-moving inner planet transfers energy to dust particles, moving them outward, deeper into the ring. Slower-moving outer planet removes energy from the particles, causing them to drop inward. Credit CREDIT: Bill Saxton, NRAO/AUI/NSF Usage Restrictions Reproduce the credit 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.