1566 Icarus
Radar image of Icarus taken by the Goldstone Observatory in June 2015
Discovery[1]
Discovered byW. Baade
Discovery sitePalomar Obs.
Discovery date27 June 1949
Designations
(1566) Icarus
Pronunciation/ˈɪkərəs/[2]
Named after
Icarus[3] (Greek mythology)
1949 MA
AdjectivesIcarian /aɪˈkɛəriən/[5]
Symbol (astrological)
Orbital characteristics[4]
Epoch 1 July 2021 (JD 2459396.5)
Uncertainty parameter 0
Observation arc72.11 yr (26,339 d)
Aphelion1.9697 AU
Perihelion0.1865 AU
1.0781 AU
Eccentricity0.8270
1.12 yr (409 d)
180.73°
0° 52m 49.8s / day
Inclination22.812°
87.981°
31.419°
Earth MOID0.0341 AU (13.3 LD)
Physical characteristics
Dimensions1.61 km × 1.60 km × 1.17 km[6]
Mean diameter
16.35[1][4]

1566 Icarus (/ˈɪkərəs/ IK-ə-rəs; provisional designation: 1949 MA) is a large near-Earth object of the Apollo group and the lowest numbered potentially hazardous asteroid.[20] It has an extremely eccentric orbit (0.83) and measures approximately 1.4 km (0.87 mi) in diameter. In 1968, it became the first asteroid ever observed by radar.[3] Its orbit brings it closer to the Sun than Mercury and further out than the orbit of Mars, which also makes it a Mercury-, Venus-, and Mars-crossing asteroid. This stony asteroid and relatively fast rotator with a period of 2.27 hours was discovered on 27 June 1949, by German astronomer Walter Baade at the Palomar Observatory in California.[1] It was named after the mythological Icarus.[3]

Orbit and classification

Orbital diagram of Icarus

Icarus orbits the Sun at a distance of 0.19–1.97 AU once every 13 months (409 days; semi-major axis of 1.08 AU). Its orbit has an eccentricity of 0.83 and an inclination of 23° with respect to the ecliptic.[4] The body's observation arc begins with its official discovery observation at Palomar in 1949.[1]

At perihelion, Icarus comes closer to the Sun than Mercury, i.e. it is a Mercury-crossing asteroid. It is also a Venus and Mars-crosser. From 1949 until the discovery of 3200 Phaethon in 1983, it was known as the asteroid that passed closest to the Sun. Since then hundreds of Mercury-crossers have been found, the closest ones are now being 2005 HC4 and (394130) 2006 HY51 (also see List of Mercury-crossing minor planets § List).

Meteor shower

Icarus is thought to be the source of the Arietids,[21] a strong daylight meteor shower. However other objects such as the short-period Sun-grazing comet 96P/Machholz are also possible candidates for the shower's origin.[22]

Close approaches

Icarus has an Earth minimum orbital intersection distance of 0.0352 AU (5,270,000 km), which translates into 13.7 lunar distances (LD).[4] This near-Earth object and potentially hazardous asteroid makes close approaches to Earth in June at intervals of 9, 19, or 28 years.

On 14 June 1968, it came as close as 0.042482 AU (6,355,200 km; 16.533 LD).[23] During this approach, Icarus became the first minor planet to be observed using radar, with measurements obtained at the Haystack Observatory[24] and the Goldstone Tracking Station.[25]

The last close approach was on 16 June 2015, when Icarus passed Earth at 0.05383 AU (8,053,000 km; 20.95 LD).[6][23] Before that, the previous close approach was on 11 June 1996, at 0.10119 AU (15,138,000 km), almost 40 times as far as the Moon. The next notably close approach will be on 13 June 2043, at 0.0586 AU (8,770,000 km) from Earth.[23]

Naming

This minor planet was named after Icarus, son of Daedalus (also see 1864 Daedalus) from Greek mythology. They attempted to escape prison by means of wings constructed from feathers and wax. Icarus ignored his father's instructions not to fly too close to the Sun. When the wax in his wings melted he fell into the sea and drowned.[3] The naming was suggested by R. C. Cameron and Dr. Folkman. The official naming citation was published by the Minor Planet Center in January 1950 (M.P.C. 347).[26] Both mythological figures are honored with the lunar craters Icarus and Daedalus.[3]

Physical characteristics

Radiometric observation characterized Icarus as a stony S-type and Q-type asteroid.[19]

Rotation period

Since 1968, several rotational lightcurves of Icarus were obtained from photometric and radiometric observations.[10][13][14] During the asteroid's close approach in June 2017, observations of the fast-moving object were taken by Italian astronomers Virginio Oldani and Federico Manzini, Brian Warner at the Palmer Divide Station (U82) in California, and by Australian astronomers at the Darling Range and Blue Mountains Observatories (Q68).[11][12][15][b]

Lightcurve analysis gave it a consolidated rotation period of 2.2726 hours with a brightness variation of 0.22 magnitude (U=3).[18][b] Icarus is a relatively fast rotator, near the threshold where non-solid rubble piles fly apart.

Spin axis

Analysis of 2015 radar observations obtained at the Arecibo Observatory and the Goldstone Observatory yields a spin axis of (270.0°, −81.0°) in ecliptic coordinates (λ, β).[6]

Diameter and albedo

According to several radiometric, photometric, and radar observations, including the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Icarus measures between 1.0 and 1.44 kilometers in diameter and its surface has an albedo between 0.14 and 0.51.[7][8][9][6][16][a]

Analysis of the radar data obtained at the Arecibo and Goldstone observatories in June 2015 gives the body's dimensions: 1.61 × 1.60 × 1.17 kilometers, with equivalent diameter of 1.44 kilometers.[6] The Collaborative Asteroid Lightcurve Link adopts an albedo of 0.14 based on the radar-derived equivalent diameter of 1.44 kilometers and absolute magnitude of 16.96.[18]

Research interests

Icarus is being studied to better understand general relativity, solar oblateness, and Yarkovsky drift.[27][28] In its case, the perihelion precession caused by general relativity is 10.05 arcseconds per Julian century.[27][28]

Project Icarus

"Project Icarus" was a student project conducted at the Massachusetts Institute of Technology (MIT) in the spring of 1967 as a contingency plan in case of an impending collision with 1566 Icarus.

This project was an assignment by Paul Sandorff for his group of MIT systems engineering graduate students to devise a plan to use rockets to deflect or destroy Icarus in the case that it was found to be on a collision course with planet Earth.[29][30][31] Time magazine ran an article on the endeavor in June 1967[30] and the following year the student report was published as a book.[29][31][32]

The students' plan relied on the new Saturn V rocket, which did not make its first flight until after the report had been completed. During the course of their study, the students visited the Kennedy Space Center, Florida, where they were so impressed with the Vehicle Assembly Building that they wrote of "the awesome reality" that had "completely erased" their doubts over using the technology associated with the Apollo program and Saturn rockets.

The final plan hypothesized that six Saturn V rockets (appropriated from the then-current Apollo program) would be used, each launched at variable intervals from months to hours away from impact. Each rocket was to be fitted with a single 100-megaton nuclear warhead as well as a modified Apollo Service Module and uncrewed Apollo Command Module for guidance to the target. The warheads would be detonated 30 meters from the surface, deflecting or partially destroying the asteroid. Depending on the subsequent impacts on the course or the destruction of the asteroid, later missions would be modified or cancelled as needed. The "last-ditch" launch of the sixth rocket would be 18 hours prior to impact.[33]

In fiction

The report later served as the basis and inspiration for the 1979 science fiction film Meteor.[31][34]

"Summertime on Icarus" is a science fiction short story by British writer Arthur C. Clarke.

Notes

  1. ^ a b c Hazards due to Comets and Asteroids (1994), Ed. T. Gehrels, pp. 540–543 at JPL's SBDB
  2. ^ a b Lightcurve plot of (1566) Icarus by Brian Warner at CS3-PDS (2015). Summary figures at the LCDB

References

  1. ^ a b c d e "1566 Icarus (1949 MA)". Minor Planet Center. Retrieved 30 August 2021.
  2. ^ "Icarus". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  3. ^ a b c d e Schmadel, Lutz D. (2007). "(1566) Icarus". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 124. doi:10.1007/978-3-540-29925-7_1567. ISBN 978-3-540-00238-3.
  4. ^ a b c d e f g "JPL Small-Body Database Browser: 1566 Icarus (1949 MA)" (2021-08-11 last obs.). Jet Propulsion Laboratory. Retrieved 30 August 2021.
  5. ^ "Icarian". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  6. ^ a b c d e f g Greenberg, Adam H.; Margot, Jean-Luc; Verma, Ashok K.; Taylor, Patrick A.; Naidu, Shantanu P.; Brozovic, Marina.; et al. (March 2017). "Asteroid 1566 Icarus's Size, Shape, Orbit, and Yarkovsky Drift from Radar Observations". The Astronomical Journal. 153 (3): 16. arXiv:1612.07434. Bibcode:2017AJ....153..108G. doi:10.3847/1538-3881/153/3/108. S2CID 28388555.
  7. ^ a b c Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. S2CID 9341381.
  8. ^ a b c Harris, Alan W. (February 1998). "A Thermal Model for Near-Earth Asteroids". Icarus. 131 (2): 291–301. Bibcode:1998Icar..131..291H. doi:10.1006/icar.1997.5865.
  9. ^ a b c Mainzer, A.; Grav, T.; Masiero, J.; Bauer, J.; Cutri, R. M.; McMillan, R. S.; et al. (November 2012). "Physical Parameters of Asteroids Estimated from the WISE 3-Band Data and NEOWISE Post-Cryogenic Survey". The Astrophysical Journal Letters. 760 (1): 6. arXiv:1210.0502. Bibcode:2012ApJ...760L..12M. doi:10.1088/2041-8205/760/1/L12. S2CID 41459166.
  10. ^ a b Miner, E.; Young, J. (May 1969). "Photometric Determination of the Rotation Period of 1566 Icarus". Icarus. 10 (3): 436–440. Bibcode:1969Icar...10..436M. doi:10.1016/0019-1035(69)90102-X.
  11. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1566) Icarus". Geneva Observatory. Retrieved 21 September 2017.
  12. ^ a b Warner, Brian D. (October 2015). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 March-June". The Minor Planet Bulletin. 42 (4): 256–266. Bibcode:2015MPBu...42..256W. ISSN 1052-8091. PMC 7244091. PMID 32455361.
  13. ^ a b Gehrels, T.; Roemer, E.; Taylor, R. C.; Zellner, B. H. (March 1970). "Minor planets and related objects. IV. Asteroid (1566) Icarus". Astronomical Journal. 75: 186–195. Bibcode:1970AJ.....75..186G. doi:10.1086/110962.
  14. ^ a b De Angelis, G. (May 1995). "Asteroid spin, pole and shape determinations". Planetary and Space Science. 43 (5): 649–682. Bibcode:1995P&SS...43..649D. doi:10.1016/0032-0633(94)00151-G.
  15. ^ a b Oey, Julian; Williams, Hasen; Groom, Roger (July 2017). "Lightcurve Analysis of Asteroids from BMO and DRO in 2015". The Minor Planet Bulletin. 44 (3): 200–204. Bibcode:2017MPBu...44..200O. ISSN 1052-8091.
  16. ^ a b Thomas, C. A.; Trilling, D. E.; Emery, J. P.; Mueller, M.; Hora, J. L.; Benner, L. A. M.; et al. (September 2011). "ExploreNEOs. V. Average Albedo by Taxonomic Complex in the Near-Earth Asteroid Population". The Astronomical Journal. 142 (3): 12. Bibcode:2011AJ....142...85T. doi:10.1088/0004-6256/142/3/85.
  17. ^ Veeder, G. J.; Hanner, M. S.; Matson, D. L.; Tedesco, E. F.; Lebofsky, L. A.; Tokunaga, A. T. (April 1989). "Radiometry of near-earth asteroids". Astronomical Journal. 97 (4): 1211–1219. Bibcode:1989AJ.....97.1211V. doi:10.1086/115064. ISSN 0004-6256. PMID 11538320.
  18. ^ a b c "LCDB Data for (1566) Icarus". Asteroid Lightcurve Database (LCDB). Retrieved 21 September 2017.
  19. ^ a b Mahapatra, Pravas R.; Ostro, Steven J.; Benner, Lance A. m.; Rosema, Keith D.; Jurgens, Raymond F.; Winkler, Ron; et al. (August 1999). "Recent radar observations of asteroid 1566 Icarus". Planetary and Space Science. 47 (8–9): 987–995. Bibcode:1999P&SS...47..987M. doi:10.1016/S0032-0633(99)00015-X.
  20. ^ "List of the Potentially Hazardous Asteroids (PHAs)". Minor Planet Center. 20 September 2017. Retrieved 21 September 2017.
  21. ^ Daylight Meteors: The Arietids @spaceweather.com
  22. ^ Ohtsuka, Katsuhito; Nakano, Syuichi; Yoshikawa, Makoto (2003), "On the Association among Periodic Comet 96P/Machholz, Arietids, the Marsden Comet Group, and the Kracht Comet Group", Publications of the Astronomical Society of Japan, 55: 321–324, doi:10.1093/pasj/55.1.321
  23. ^ a b c "JPL Close-Approach Data: 1566 Icarus (1949 MA)" (2015-07-31 last obs.). Retrieved 21 September 2017.
  24. ^ Pettengill, G. H.; Shapiro, I. I.; Ash, M. E.; Ingalls, R. P.; Rainville, L. P.; Smith, W. B.; et al. (May 1969). "Radar observations of Icarus". Icarus. 10 (3): 432–435. Bibcode:1969Icar...10..432P. doi:10.1016/0019-1035(69)90101-8. ISSN 0019-1035.
  25. ^ Goldstein, R. M. (November 1968). "Radar Observations of Icarus". Science. 162 (3856): 903–904(SciHomepage). Bibcode:1968Sci...162..903G. doi:10.1126/science.162.3856.903. PMID 17769079. S2CID 129644095.
  26. ^ Schmadel, Lutz D. (2009). "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. Bibcode:2009dmpn.book.....S. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.
  27. ^ a b "Asteroids with high perihelion precession rates". UCLA. Retrieved 19 June 2015.
  28. ^ a b Verma, Ashok K.; Margot, Jean-Luc; Greenberg, Adam H. (August 2017). "Prospects of Dynamical Determination of General Relativity Parameter β and Solar Quadrupole Moment with Asteroid Radar Astronomy". The Astrophysical Journal. 845 (2): 166. arXiv:1707.08675. Bibcode:2017ApJ...845..166V. doi:10.3847/1538-4357/aa8308. ISSN 0004-637X. S2CID 20331818.
  29. ^ a b Kleiman, Louis A., Project Icarus: an MIT Student Project in Systems Engineering Archived 17 October 2007 at the Wayback Machine, Cambridge, Massachusetts: MIT Press, 1968
  30. ^ a b "Systems Engineering: Avoiding an Asteroid", Time magazine, 16 June 1967.
  31. ^ a b c Day, Dwayne A., "Giant bombs on giant rockets: Project Icarus", The Space Review, 5 July 2004.
  32. ^ Project Icarus Archived 17 October 2007 at the Wayback Machine, MIT Report No. 13, MIT Press 1968, edited by Louis A. Kleiman. "Interdepartmental Student Project in Systems Engineering at the Massachusetts Institute of Technology, Spring Term, 1967"; reissued 1979.
  33. ^ David S. F. Portree. "MIT Saves the World: Project Icarus (1967)". Wired. Wired Science. Retrieved 21 October 2013.
  34. ^ "MIT Course precept for movie" Archived 4 November 2016 at the Wayback Machine, The Tech, MIT, 30 October 1979

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