| Minorplanet: | yes |
| Background: |
|
| 205 Martha | |
| Discovered: | 13 October 1879 |
| Mpc Name: | (205) Martha |
| Pronounced: | [1] |
| Alt Names: | A879 TB |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Semimajor: | 2.7771AU |
| Perihelion: | 2.6783AU |
| Aphelion: | 2.8758abbr=onNaNabbr=on |
| Eccentricity: | 0.035571 |
| Period: | 4.63 yr (1690.3 d) |
| Inclination: | 10.696° |
| Asc Node: | 211.792° |
| Arg Peri: | 177.281° |
| Avg Speed: | 17.87 km/s |
| Rotation: | 14.911abbr=onNaNabbr=on |
| Abs Magnitude: | 9.23 |
| Mean Motion: | / day |
| Orbit Ref: | [2] |
| Observation Arc: | 136.51 yr (49860 d) |
| Uncertainty: | 0 |
205 Martha is a large main belt asteroid. It is a dark, primitive carbonaceous C-type asteroid. This object was discovered by Johann Palisa on 13 October 1879, in Pola and was named after Martha, a woman in the New Testament.
Efforts to determine the rotation period for this asteroid have produced wildly different results, in large part because the actual period is close to half of an Earth day. A study performed during 2013 showed that the light curve changed significantly during the observation period, adding to the difficulty. This study gave a synodic rotation period of 14.905 ± 0.001 h.