70 Panopaea

Panopaea (minor planet designation: 70 Panopaea) is a large main belt asteroid. Its orbit is close to those of the Eunomia asteroid family; however, Panopaea is a dark, primitive carbonaceous C-type asteroid in contrast to the S-type asteroids of the Eunomian asteroids. The spectra of the asteroid displays evidence of aqueous alteration.[10] Photometric studies give a rotation period of 15.797 hours and an amplitude of 0.11±0.01 in magnitude. Previous studies that suggested the rotation period may be twice this amount were rejected based upon further observation.[11]

Panopaea was discovered by Hermann Goldschmidt on 5 May 1861.[1] It was his fourteenth and last asteroid discovery. It is named after Panopea, a nymph in Greek mythology; the name was chosen by Robert Main, President of the Royal Astronomical Society.[12] In 1862, Swedish astronomer Nils Christoffer Dunér gave a doctoral thesis on the orbital elements of this asteroid.[13]

The orbit of 70 Panopaea places it in a mean motion resonance with the planets Jupiter and Saturn. The computed Lyapunov time for this asteroid is 24,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets.[14]

The asteroid frequently makes close approaches with 16 Psyche, such as on 12 June 2040 when it will make a close approach of 0.00602 AU (2.34 Lunar distances, or approx. 770,000 km, 478,455 mi) to the asteroid, and on 2 June 2095 when it will come only 0.003372 AU (1.31 LD) to the asteroid.[3]