Asteroid 4581, a member of the Apollo group, discovered in 1989 by the American astronomers Henry Edward Holt (1929– ) and Norman Gene Thomas (1930– ). It can approach to within 0.004 au (600 000 km) of Earth’s orbit. Asclepius is about 400 m in diameter. Its orbit has a semimajor axis of 1.02 au, period 1.03 years, perihelion 0.66 au, aphelion 1.39 au, and inclination 4°.9.