155221

155221 is a minor planet in the asteroid belt, discovered on September 1, 1995, by astronomers at the Spacewatch program at Kitt Peak National Observatory. It is classified as a main-belt asteroid, orbiting the Sun between Mars and Jupiter. The asteroid is approximately 3 kilometers in diameter and has an orbital period of about 3.6 Earth years. Its rotation period is estimated to be around 5.5 hours. 155221 is named after the Spacewatch program, which has been instrumental in the discovery and tracking of numerous near-Earth objects and main-belt asteroids. The naming citation was published by the Minor Planet Center on March 2, 2003.