343158 Marsyas

343158 Marsyas
Discovery [1][2]
Discovered byCSS
Discovery siteCatalina Stn.
Discovery date29 April 2009
Designations
(343158) Marsyas
Named after
Marsyas [1][3]
(Greek mythology)
2009 HC82
NEO · Apollo[1][4]
Retrograde
Orbital characteristics [4]
Epoch 17 December 2020 (JD 2459200.5)
Uncertainty parameter 0
Observation arc17.17 yr (6,270 d)
Aphelion4.5656 AU
Perihelion0.4886 AU
2.5271 AU
Eccentricity0.8067
4.02 yr (1,467 d)
5.8661°
0° 14m 43.08s / day
Inclination154.37°
295.40°
298.88°
Earth MOID0.1471 AU (57.2 LD)
TJupiter1.3160
Physical characteristics
1.7 km (est. at 0.22)[5]
3.5 km (est. at 0.05)[5]
~20[2]
16.27[1][4]

343158 Marsyas (prov. designated 2009 HC82) is an asteroid on a retrograde orbit, classified as a large near-Earth object of the Apollo group. It may be an extinct comet or damocloid asteroid. The asteroid was discovered on 29 April 2009, by astronomers with the Catalina Sky Survey at the Catalina Station near Tucson, Arizona, in the United States.[1] Approximately 2 kilometers (1.2 miles) in diameter, it makes many close approaches to Earth, Venus, and Mars at a very high relative velocity. It was named after the satyr Marsyas from Greek mythology.[1][3]

Classification and orbit

Marsyas was initially listed as a potentially hazardous asteroid.[2] It was removed from the Sentry Risk Table on 6 May 2009.[6] It orbits the Sun at a distance of 0.49–4.6 AU once every 4.02 years (1,467 days; semi-major axis of 2.53 AU). Its orbit has an eccentricity of 0.81 and an inclination of 154° with respect to the ecliptic.[4]

Retrograde

Marsyas has a retrograde orbit and thus orbits the Sun in the opposite direction of other objects. Therefore, close approaches to this object can have very high relative velocities. As of 2012, it had the highest relative velocity to Earth of objects that come within 0.5 AU of Earth.[7]

Close approaches

On 11 November 2024, Marsyas will pass about 0.485 AU (72,600,000 km; 45,100,000 mi) from Earth, but with a record high relative velocity of about 283,000 km/h (78.66 km/s).[8] Both Halley's Comet (254,000 km/h)[9] and 55P/Tempel-Tuttle (252,800 km/h)[10] have slightly lower relative velocities to Earth. Note however that when the asteroid is one astronomical unit from the sun (as it would be if it ever hit the earth), its relative speed will be less. On 2 February 2053, Marsyas will pass about 0.08 AU from Venus.[8] On 22 October 2060, it may pass about 0.004 AU (600,000 km; 370,000 mi) from Mars.[8]

Possible damocloid

The multiple planet crossing and retrograde orbit suggests that this object may be an extinct comet or damocloid asteroid similar to 5335 Damocles, 2008 KV42, and 20461 Dioretsa.[11]

Possible asteroid origin

Marsyas has a semimajor axis that puts it very near the 3:1 mean-motion resonance with Jupiter at 2.5 au. This resonance has been shown to be a source for near-Earth asteroids on low-inclination orbits to evolve onto retrograde orbits.[12][13] Studies[13] show that, when compared to model predictions,[12] Marsyas exhibits orbital behavior very similar to near-Earth asteroids that undergo the transition to retrograde orbits. Its orbital evolution and current location very near the 3:1 resonance strongly suggests that Marsyas thus may likely to be a near-Earth asteroid that evolved onto a retrograde orbit as opposed to being an extinct comet or damacloid asteroid.

Diameter

Based on a generic magnitude-to-diameter conversion, Marsyas measures approximately 1.7 to 3.5 kilometers in diameter, for an absolute magnitude of 16.2 and an assumed albedo between 0.22 and 0.05. Since the true albedo is unknown and it has an absolute magnitude (H) of 16.1,[4] it is about 1.6 to 3.6 km in diameter.[5]

Naming

On 14 May 2021, the object was named by the Working Group for Small Bodies Nomenclature (WGSBN),[3] after Marsyas, a Phrygian satyr from Greek mythology, who dared to challenge Apollo in a musical contest. Marsyas lost and he was flayed alive in a cave near Celaenae for his hubris to challenge a god. As with the mythological account, the unusual retrograde orbit of asteroid Marsyas is opposed to most bodies in the Solar System, including 1862 Apollo.[1]

References

  1. ^ a b c d e f g "(343158) Marsyas". Minor Planet Center. Retrieved 18 May 2021.
  2. ^ a b c "MPEC 2009-J04 : 2009 HC82". IAU Minor Planet Center. 1 May 2009. Retrieved 18 May 2021.
  3. ^ a b c "WGSBN Bulletin Archive". Working Group for Small Bodies Nomenclature. 14 May 2021. Retrieved 16 May 2021. (Bulletin #1)
  4. ^ a b c d e "JPL Small-Body Database Browser: 343158 Marsyas" (2021-05-18 last obs.). Jet Propulsion Laboratory. Retrieved 18 May 2021.
  5. ^ a b c "Asteroid Size Estimator". CNEOS NASA/JPL. Retrieved 26 January 2018.
  6. ^ "Date/Time Removed". NASA/JPL Near-Earth Object Program Office. Archived from the original on 2 June 2002. Retrieved 19 March 2012.
  7. ^ "NEO Close-Approaches (Between 1900 and 2200)". NASA/JPL Near-Earth Object Program. Archived from the original on 13 December 2012. Retrieved 22 June 2012. (sorted by descending relative velocity, dist<0.5AU = "215,221 close-Earth approaches")
  8. ^ a b c "JPL Close-Approach Data: (2009 HC82)" (last observation: 2010-04-04). Retrieved 9 February 2011.
  9. ^ "JPL Close-Approach Data: 1P/Halley" (last observation: 1994-01-11). Retrieved 9 February 2011.
  10. ^ "JPL Close-Approach Data: 55P/Tempel-Tuttle" (last observation: 1998-07-05). Retrieved 9 February 2011.
  11. ^ Akimasa Nakamura and bas (2 May 2009). "List of Damocloids (Oort cloud asteroids)". Lowell Observatory. Retrieved 9 February 2011.
  12. ^ a b Greenstreet, Sarah; Ngo, Henry; Gladman, Brett (January 2012). "The orbital distribution of Near-Earth Objects inside Earth's orbit" (PDF). Icarus. 217 (1): 355–366. Bibcode:2012Icar..217..355G. doi:10.1016/j.icarus.2011.11.010. hdl:2429/37251. There are two known retrograde NEAs: 2007 VA85 (a = 4.226 AU, e = 0.736, i = 131.769°) and 2009 HC82 (a = 2.528 AU, e = 0.807, i = 154.519°).
  13. ^ a b Greenstreet, Sarah; Gladman, Brett; Ngo, Henry; Granvik, Mikael; Larson, Steve (April 2012). "Production of near-Earth asteroids on retrograde orbits" (PDF). The Astrophysical Journal Letters. 749 (2): L39–L43. Bibcode:2012ApJ...749L..39G. doi:10.1088/2041-8205/749/2/L39. S2CID 121886308. 2009 HC82, on the other hand, is on an orbit very near the 3:1 resonance (where it most likely flipped) for the entirety of both independent 1 Myr integrations of the best-fit orbit. This behavior is exactly like the typical steady-state retrograde NEA evolution we discovered.