| Minorplanet: | yes |
| Background: |
|
| Aphelion: | 516.955 Gm (3.456 AU) |
| Period: | 1761.647 d (4.82 a) |
| Mean Anomaly: | 149.581° |
| Dimensions: | 121.77 ± 2.34 km |
| Density: | 6.54 ± 5.62 g/cm3 |
| Abs Magnitude: | 8.48 |
| 81 Terpsichore | |
| Discovered: | 30 September 1864 |
| Mpc Name: | (81) Terpsichore |
| Adjective: | Terpsichorean |
| Epoch: | 31 December 2006 (JD 2454100.5) |
| Semimajor: | 427.044 Gm (2.855 AU) |
| Perihelion: | 337.132 Gm (2.254 AU) |
| Eccentricity: | 0.211 |
| Inclination: | 7.809° |
| Asc Node: | 1.497° |
| Arg Peri: | 50.234° |
| Avg Speed: | 17.43 km/s |
| Rotation: | 10.943 hr |
| Albedo: | 0.051 [1] |
81 Terpsichore is a large and very dark main-belt asteroid. It has most probably a very primitive carbonaceous composition. It was found by the prolific comet discoverer Ernst Tempel on 30 September 1864. It is named after Terpsichore, the Muse of dance in Greek mythology.
Photometric observations of the minor planet in 2011 gave a rotation period of with an amplitude of in magnitude. This result is consistent with previous determinations. Two stellar occultation events involving this asteroid were observed from multiple sites in 2009. The resulting chords matched a smooth elliptical cross-section with dimensions of × .
A space station orbiting 81 Terpsichore is the main setting in the science fiction story The Dark Colony (Asteroid Police Book 1) by Richard Penn.