3 Juno was the third asteroid to be discovered, in 1804 by K. Harding.
Orbital characteristics Orbit type Main belt Semimajor axis 2.669 AU Eccentricity 0.2579 Orbital period 4.36 years Inclination 12.97° Physical characteristics Diameter 240 km Mass 2.0×1019 kg Density ? g/cm3 Rotation period 7h 12m Spectral class S[?] Albedo 0.16 History Discoverer K. Harding[?], 1804