| Minorplanet | yes |
|---|---|
| Background |
|
| Discoverer | Carlos Torres |
| Discovery site | Cerro El Roble |
| Discovered | 24 April 1982 |
| Mpc name | (3361) Orpheus |
| Alt names | 1982 HR |
| Pronounced | /ˈɔrfiːəs,_ˈɔrfjuːs/ |
| Adjective | Orphean (Orphæan) /ɔrˈfiːən/[1] |
| Named after | Orpheus, a legendary Greek bard and prophet |
| Mp category | PHA[2] |
| Epoch | 13 June 2008 (JD 2454630.5) |
| Aphelion | 1.5999 AU |
| Perihelion | 0.81893 AU |
| Semimajor | 1.2094 AU |
| 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[2] |
| Abs magnitude | 19.03[2] |
| Mean motion | / day |
| Rotation | 3.532 h[2] |
| Mean radius | 0.15 km |
| Observation arc | 11752 days (32.18 yr) |
| Uncertainty | 0 |
| Moid | 0.0139175 AU (2,082,030 km; 1,293,710 mi) |
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 those of Mars and Earth, and approaches Venus as well. From 1900 to 2100 it passes closer than 0.2 astronomical units to Venus, 11; Earth, 33; and Mars, 14 times. It passed by Earth at a distance of about 0.03 astronomical units in 1937, 1978, 1982, and 2021, and will do so again in 2025.[2]
3361 Orpheus is a potentially hazardous asteroid (PHA) because its minimum orbit intersection distance (MOID) is less than 0.05 astronomical units and its diameter is greater than 140 metres (460 ft). The Earth-MOID is 0.0139 astronomical units.[2] 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.[2]
| Date | JPL SBDB nominal geocentric distance | uncertainty region (3-sigma) |
|---|---|---|
| 2021-11-21 | 5,768,611 km | ± 18 km |
| 2198-04-16 | 3,908,508 km | ± 129 km[3] |
Missions
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.[4][clarification needed]
References
- ^
- ^ "JPL Small-Body Database Browser: 3361 Orpheus (1982 HR)" (last observation: 17 November 2021). Jet Propulsion Laboratory. Retrieved 20 November 2021.
- ^ "Horizons Batch for 2198-Apr-16 Close Approach". JPL Horizons. Archived 2022-10-17 at the Wayback Machine. Retrieved 2022-10-17. RNG_3sigma = uncertainty range in km. (JPL#179/Soln.date: 2022-Mar-23 generates RNG_3sigma = 129 km)
- ^ Cheng, A.F.; Michel, P.; Jutzi, M.; Rivkin, A.S.; Stickle, A.; Barnouin, O.; Ernst, C.; Atchison, J.; Pravec, P.; Richardson, D.C. (2016). "Asteroid Impact & Deflection Assessment mission: Kinetic impactor". Planetary and Space Science. 121: 27–35. Bibcode:2016P&SS..121...27C. doi:10.1016/j.pss.2015.12.004. hdl:11104/0261023