2101 Adonis

2101 Adonis is a small asteroid that is a member of the Apollo group; it was discovered by Eugene Delaporte in 1936. Adonis was the second Apollo asteroid to be found and may be an extinct comet. In 1937 it came to within 2 million kilometers of the Earth, but was then lost until recovered in 1977, by Charles Kowal, following recomputation of its orbit.

diameter about 1 km
semimajor axis 1.874 AU
perihelion 0.441 AU
aphelion 3.307 AU
inclination 1.35°
period 2.56 years (936.7 d)