2101 Adonis

2101 Adonis
Discovery [1]
Discovered by E. Delporte
Discovery site Uccle Obs.
Discovery date 12 February 1936
Designations
MPC designation (2101) Adonis
Named after
 Adonis
(Greek mythology)[2]
1936 CA
NEO · PHA · Apollo [1][3]
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 78.20 yr (28,561 days)
Aphelion 3.3067 AU
Perihelion 0.4407 AU
1.8737 AU
Eccentricity 0.7648
2.56 yr (937 days)
311.98°
0° 23m 3.48s / day
Inclination 1.3257°
349.63°
43.474°
Earth MOID 0.0116 AU · 4.5 LD
Physical characteristics
Dimensions 0.523 km (est. at 0.20)[4]
0.6 km (Gehrels est.)[1]
18.8[1][4]

    2101 Adonis, provisional designation 1936 CA, is an extremely eccentric asteroid, classified as potentially hazardous asteroid and near-Earth object of the Apollo group, approximately 1 kilometer in diameter. Discovered by Eugène Delporte at Uccle in 1936, it became a lost asteroid until 1977. It may also be an extinct comet and a source of meteor showers.[5] It was named after Adonis from Greek mythology.[2]

    Discovery

    Adonis was discovered on 12 February 1936, by Belgian astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle.[3] After its initial discovery, which happened during a close approach with Earth, the asteroid was observed for two months, before it became a lost asteroid, as not enough observations could be made to calculate a sufficiently accurate orbit. It took 41 years until it was finally rediscovered by the American astronomer Charles Kowal in 1977, based on mathematical predictions made by Dr. Brian Marsden.

    Orbit and classification

    The near-Earth object orbits the Sun at a distance of 0.4–3.3 AU once every 2 years and 7 months (937 days). Its orbit has an eccentricity of 0.76 and an inclination of 1° with respect to the ecliptic.[1]

    Adonis was one of the first near-Earth objects ever to be discovered. It was also the second known Apollo asteroid after 1862 Apollo, the group's namesake discovered four years earlier in 1932.

    MOID

    It is a potentially hazardous asteroid because its Earth minimum orbit intersection distance of 0.0116 AU (1,740,000 km), or 4.5 lunar distances, is less than 0.05 AU and its diameter is greater than 150 meters. It also makes close approaches to Venus and Mars and comes within 30 Gm of the Earth six times in the 21st century, the nearest being 0.03569 AU (5,340,000 km) on 7 February 2036.[1][6][7]

    Physical characteristics

    Adonis has an absolute magnitude of 18.8, and an estimated mean-diameter between 520 and 600 meters.[1][4] As of 2017, the body's rotation period, composition, spectral type and shape remain unknown.[1][8]

    Naming

    This minor planet is named from Greek mythology after the handsome, ever-youthful vegetation god Adonis, with whom the goddess Aphrodite fell in love. Persephone was also taken by Adonis' beauty and refused to give him back to Aphrodite. The dispute between the two goddesses was settled by Zeus: Adonis was to spend one-third of every year with each goddess and the last third wherever he chose. He was killed by a boar sent by Artemis. The minor planets 105 Artemis, 399 Persephone, 1388 Aphrodite and 5731 Zeus were named for these Greek gods.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 4548).[9]

    Exploration

    Adonis was considered as a possible target for a 6 million km distant flyby by the Vega 2 spacecraft after its 1986 flyby of Halley's comet.[10] In the event Vega 2 didn't have enough fuel post Halley encounter to make the necessary orbital changes for the flyby.[10]

    References

    1. 1 2 3 4 5 6 7 8 9 "JPL Small-Body Database Browser: 2101 Adonis (1936 CA)" (2014-04-24 last obs.). Jet Propulsion Laboratory. Retrieved 11 June 2017.
    2. 1 2 3 Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (2101) Adonis. Springer Berlin Heidelberg. p. 170. ISBN 978-3-540-00238-3. Retrieved 4 June 2016.
    3. 1 2 "2101 Adonis (1936 CA)". Minor Planet Center. Retrieved 4 June 2016.
    4. 1 2 3 "(2101) Adonis – PHYSICAL INFORMATION". NEODyS—Near Earth Objects - Dynamic Site. Retrieved 1 August 2015.
    5. ↑ Babadzhanov, P. B. (2003). "Meteor showers associated with the near-Earth asteroid (2101) Adonis". Astronomy and Astrophysics. 397 (1): 319–323. Bibcode:2003A&A...397..319B. doi:10.1051/0004-6361:20021506.
    6. ↑ "JPL Close-Approach Data: 2101 Adonis (1936 CA)" (2008-03-10 last obs.). Retrieved 5 May 2009.
    7. ↑ "NEODys (2101) Adonis". Department of Mathematics, University of Pisa, ITALY. Retrieved 5 May 2009.
    8. ↑ "LCDB Data for (2101) Adonis". Asteroid Lightcurve Database (LCDB). Retrieved 11 June 2017.
    9. ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 June 2016.
    10. 1 2 Ulivi, Paolo; Harland, David M (2009). Robotic Exploration of the Solar System Part 2 Hiatus and Renewal. Praxis Publishing. pp. 90–92. ISBN 9780387789040.
    11. "Brian Marsden, Tracker of Comets, Dies at 73". The New York Times. Retrieved 22 November 2010.
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