File:How Sunlight Pushes Asteroids

English: Near-Earth asteroids like Bennu pose a potential danger to our planet, so it's important to predict their orbits with great accuracy. Unfortunately, a phenomenon called the Yarkovsky effect can make these predictions difficult over long time periods. How does this effect work? When sunlight strikes a rotating asteroid, the dayside heats up; as the asteroid turns, the night side cools and releases the heat, exerting a small thrust that can change the asteroid's direction over time. In order to learn more about this process on asteroid Bennu, NASA is sending a spacecraft called OSIRIS-REx to make detailed observations of Bennu's shape, brightness, and surface features. These factors are thought to influence the Yarkovsky effect, and understanding how will enable scientists to better predict the orbit of Bennu and other near-Earth asteroids.