The Hubble Space Telescope has taken a detailed image of a narrow, dusty ring around nearby star Fomalhaut. Although they can’t see it directly, astronomers think a planet has been tugging at the ring with its gravity. According to researchers, the shape and position of the ring couldn’t exist without a planet. This is similar to the twists and knots that NASA’s Cassini spacecraft has photographed in Saturn’s rings, which are caused by its shepherd moons.