| Minorplanet: | yes |
| Background: |
|
| 149 Medusa | |
| Discovered: | 21 September 1875 |
| Mpc Name: | (149) Medusa |
| Alt Names: | A875 SA; 1905 BA; 1906 HB |
| Orbit Ref: | [1] |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Semimajor: | 2.17472AU |
| Perihelion: | 2.03252AU |
| Aphelion: | 2.3169AU |
| Eccentricity: | 0.065386 |
| Period: | 1171.4days |
| Inclination: | 0.93927° |
| Asc Node: | 159.615° |
| Arg Peri: | 250.609° |
| Avg Speed: | 20.18 km/s |
| Mass: | 8.0 kg |
| Density: | 2.0 g/cm3 |
| Surface Grav: | 0.0055 m/s2 |
| Escape Velocity: | 0.0104 km/s |
| Abs Magnitude: | 10.79 |
| Rotation: | 26.023abbr=onNaNabbr=on 26.038 h |
| Mean Motion: | / day |
| Observation Arc: | 124.55 yr (45493 d) |
| Uncertainty: | 0 |
| Moid: | 1.04123AU |
| Jupiter Moid: | 2.87692AU |
| Tisserand: | 3.683 |
149 Medusa is a bright-coloured, stony main-belt asteroid that was discovered by French astronomer J. Perrotin on September 21, 1875, and named after the Gorgon Medusa, a snake-haired monster in Greek mythology. It is orbiting the Sun at a distance of with a period of 1171.4days and an eccentricity of 0.065. The orbital plane is tilted slightly at an angle of 0.94° to the plane of the ecliptic.[1]
When it was discovered, Medusa was by far the smallest asteroid found (although this was not known at that time). Since then, many thousands of smaller asteroids have been found. It was also the closest asteroid to the Sun discovered up to that point, beating the long-held record of 8 Flora. It remained the closest asteroid to the Sun until 433 Eros and 434 Hungaria were found in 1898, leading to the discovery of two new families of asteroids inward from the 4:1 Kirkwood gap which forms the boundary of the main belt.
Photometric observations of this asteroid at the Organ Mesa Observatory in Las Cruces, New Mexico, during 2010 gave a light curve with a rather long rotation period of 26.038 ± 0.002 hours and a brightness variation of 0.56 ± 0.03 in magnitude.