4581 Asclepius is a small asteroid of the Apollo group that can approach Earth's orbit to within 600,000 kilometers. Asclepius was discovered in 1989 by the American astronomers Henry Holt (1929–2019) and Norman Thomas (1930–2020).

 

On 22 March 1989, Asclepius passed by Earth on at a distance of 0.00457 astronomical units  (684,000 kilometers or 425,000 miles).

 

diameter	several hundred meters
semimajor axis	1.023 AU
perihelion	0.66 AU
aphelion	1.39 AU
inclination	4.9°
period	1.03 years