| Minorplanet: | yes |
| Background: |
|
| 3361 Orpheus | |
| Discoverer: | Carlos Torres |
| Discovery Site: | Cerro El Roble |
| Discovered: | 24 April 1982 |
| Mpc Name: | (3361) Orpheus |
| Alt Names: | 1982 HR |
| Adjective: | Orphean (Orphæan) |
| Named After: | Orpheus, a legendary Greek bard and prophet |
| Mp Category: | PHA |
| Epoch: | 13 June 2008 (JD 2454630.5) |
| Aphelion: | 1.5999abbr=onNaNabbr=on |
| Perihelion: | 0.81893AU |
| Semimajor: | 1.2094AU |
| Eccentricity: | 0.32288 |
| Period: | 1.33 yr (485.82 d) |
| Inclination: | 2.6849° |
| Asc Node: | 189.602° |
| Mean Anomaly: | 283.408° |
| Arg Peri: | 301.651° |
| Dimensions: | 0.3 km |
| Abs Magnitude: | 19.03 |
| Mean Motion: | / day |
| Rotation: | 3.532abbr=onNaNabbr=on |
| Mean Radius: | 0.15 km |
| Observation Arc: | 11752 days (32.18 yr) |
| Uncertainty: | 0 |
| Moid: | 0.0139175AU |
3361 Orpheus (1982 HR) is an Apollo asteroid that was discovered on 24 April 1982 by Carlos Torres at Cerro El Roble Astronomical Station. Its eccentric orbit crosses that of Mars and Earth, and approaches Venus as well. From 1900 to 2100 it passes closer than 30abbr=unitNaNabbr=unit to Venus, 11; Earth, 33; and Mars, 14 times. It passed by Earth at a distance of about 0.03abbr=unitNaNabbr=unit in 1937, 1978, 1982, and 2021, and will do so again in 2025.
3361 Orpheus is a potentially hazardous asteroid (PHA) because its minimum orbit intersection distance (MOID) is less than 0.05abbr=unitNaNabbr=unit and its diameter is greater than 140m (460feet). The Earth-MOID is 0.0139abbr=unitNaNabbr=unit. With an observation arc of 36 years, the orbit is well-determined for the next several hundred years.
The orbital solution includes non-gravitational forces.
| 2021-11-21 | ± 18 km | ||
| 2198-04-16 | ± 129 km |
3361 Orpheus had been one of the originally proposed targets for the Near Earth Asteroid Rendezvous (NEAR) mission.
The proposed AIDA mission's spacecraft, Double Asteroid Redirection Test was a fly-by observation of 3361 Orpheus during its trajectory to asteroid 65803 Didymos but later cancelled.[1]