Around 83 B.C., give or take a century, comet Kiess (C/1911 N1) passed by the Sun, ejecting a cloud of dust particles. The comet returned in 1911, after completing one orbit. The dust particles were pushed by solar radiation pressure into slightly wider orbits and have been returning ever since, forming a thin ongoing stream of dust that usually passes just outside Earth's orbit. On occasion, the combined gravity of the solar system's planets moves this dust trail into Earth's path. Earth encountered this 2000-year-old dust in 1935, 1986, and 1994, causing a meteor shower known as the Aurigids.