2010 RX30

is a tiny near-Earth asteroid that passed within over Earth's surface at 09:51 UTC on 8 September 2010. It is an Aten asteroid estimated to be around in diameter with a mass of. It was discovered by the Catalina Sky Survey near Tucson, Arizona, United States alongside, a small asteroid that also encountered Earth on 8 September. Both asteroids were discovered three days prior to encounter on 5 September, and they were reported to the Minor Planet Center that day. Asteroids similar in size to and are expected to pass within the Moon's orbit every day, though they typically remain undiscovered.