(175706) 1996 FG3

(175706) 1996 FG3
Delay-Doppler radar images of 1996 FG3 and its moon from Arecibo Observatory in 2011
Discovered byR. H. McNaught
Discovery siteSiding Spring Obs.
Discovery date24 March 1996
(175706) 1996 FG3
1996 FG3
Apollo · NEO · PHA[1][2]
Orbital characteristics[2]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 0
Observation arc17.96 yr (6,560 d)
Aphelion1.4224 AU
Perihelion0.6853 AU
1.0538 AU
1.08 yr (395 d)
0° 54m 39.6s / day
Known satellites1[3][4]
(diameter: 0.49±0.08 km)[5]
(orbital period: 16.1508 h)[6]
Earth MOID0.0283 AU (11 LD)
Physical characteristics
Mean diameter
1.196±0.362 km[7]
1.55 km[8]
1.64±0.20 km[6]
1.69±0.18 km[9]
1.84±0.56 km[10]
1.90±0.28 km[11]
3.5942 h[8][9][12]
SMASS = C[2]
B–V = 0.708±0.005[8]
V–R = 0.380±0.003[8]
V–I = 0.714±0.004[8]

(175706) 1996 FG3 is a carbonaceous asteroid and binary system,[4] classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 1.7 kilometers (1.1 miles) in diameter. The primary has a spheroidal shape. Its minor-planet moon measures approximately 490 meters (1,600 feet) in diameter.

It was discovered on 24 March 1996, by Australian astronomer Robert McNaught at Siding Spring Observatory in New South Wales, Australia.[1] The asteroid is a target of NASA's Janus Serenity space probe, which will launch in 2022 and arrive in 2026.[17] In 2017, scientists from the Chinese Academy of Sciences' Purple Mountain Observatory revealed a plan to land a probe on this asteroid in 2029, as part of an asteroid exploration mission.[18]

Numbering and naming[]

This minor planet was numbered by the Minor Planet Center on 21 February 2008.[19] As of 2021, it has not been named.[1]

Orbit and classification[]

1996 FG3 orbits the Sun at a distance of 0.7–1.4 AU once every 1 years and 1 month (395 days; semi-major axis of 1.05 AU). Its orbit has an eccentricity of 0.35 and an inclination of 2° with respect to the ecliptic.[2] It has an Earth minimum orbital intersection distance of 0.0283 AU (4,230,000 km), which corresponds to 11.0 lunar distances.[2] In 2019 a precovery observation from Palomar Mountain was found, extending the body's observation arc into 1985.[1]

Physical characteristics[]

The carbonaceous body is characterized as a rare B-type and hydrated C-type (Ch) asteroid, respectively.[11][15]


Several rotational lightcurves of this asteroid were obtained from photometric observations taken by astronomers Petr Pravec, Petr Scheirich and Stefano Mottola, as well as by the Very Large Telescope's VISR instrument. Lightcurve analysis gave a well-defined rotation period of 3.594 to 3.595 hours with a brightness variation of 0.08 to 0.10 magnitude (U=3/3/3/3).[6][8][9][12][20] The asteroid is an oblate ellipsoid with a nearly spherical shape.[6][21]

Diameter and albedo[]

According to numerous observations, including the EXPLORENEOs survey, NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission and the Spitzer Space Telescope, the asteroid measures between 1.55 and 1.90 kilometers in diameter and its surface has a low albedo of 0.03 to 0.05.[6][7][8][9][10][11] The Collaborative Asteroid Lightcurve Link adopts an albedo of 0.04 and a diameter of 1.90 kilometers.[14]


During the photometric observations in December 1998, the binary nature of this asteroid was revealed.[3][4] It was the first binary near-Earth asteroid for which eclipse events were detected in the visible spectrum.[11] The binary system has a diameter ratio of 0.28, a density of 1.4 g/cm3, and an ecliptic latitude of -84° for its mutual spin axis.[11] The asteroid moon has the S/1998 (175706) 1a designation. It has a diameter of approximately 490 meters[5], an orbital period of 16.1508 hours, and a nearly circular orbit, with an eccentricity of 0.1 and a semi-major axis of approximately 3.4 primary radii.[11]: 2  The orbital period was later estimated to be around 16.15 hours.


Rejected Marco Polo mission[]

Due to its binary nature and its low delta-v heliocentric orbit (also see Hohmann transfer orbit),[11] this asteroid was selected for MarcoPolo-R, which was the Marco Polo spacecraft's first proposed mission. MarcoPolo-R was originally selected for the assessment study phase in the M3 slot of ESA's Cosmic Vision program, but rejected in favor of PLATO by the end of 2012.[6][21]

Janus spacecraft[]

The asteroid is a target of NASA's Janus Serenity space probe, which will launch in 2022 and arrive in 2026.[22]

Planned Chinese mission[]

In 2017, Chinese scientists announced they plan to land a probe on 1996 FG3 after 2029 as part of its asteroid exploration mission.[18] The mission includes plans for fly-by of three asteroids (one of them is 99942 Apophis), and land on 1996 FG3 to conduct in situ sampling analysis on the surface, according to Ji Jianghui, a researcher at the Purple Mountain Observatory of the Chinese Academy of Sciences and a member of the expert committee for scientific goal argumentation of deep space exploration in China. The probe is also expected to conduct a fly-by of a third asteroid to be determined at a later time. The entire mission is expected to take about six years.[18]

See also[]


  1. ^ a b c d e f "175706 (1996 FG3)". Minor Planet Center. Retrieved 14 December 2016.
  2. ^ a b c d e f "JPL Small-Body Database Browser: 175706 (1996 FG3)" (2014-03-10 last obs.). Jet Propulsion Laboratory. Retrieved 12 December 2018.
  3. ^ a b "Central Bureau for Astronomical Telegrams – Circular No. 7069". IAU – International Astronomical Union. 18 December 1998. Retrieved 14 December 2016.
  4. ^ a b c "Central Bureau for Astronomical Telegrams – Circular No. 7074". IAU – International Astronomical Union. 26 December 1998. Retrieved 14 December 2016.
  5. ^ a b Johnston, Robert (16 November 2014). "(175706) 1996 FG3". johnstonsarchive.net. Retrieved 14 December 2016.
  6. ^ a b c d e f Scheirich, P.; Pravec, P.; Jacobson, S. A.; Durech, J.; Kusnirák, P.; Hornoch, K.; et al. (January 2015). "The binary near-Earth Asteroid (175706) 1996 FG3 - An observational constraint on its orbital evolution". Icarus. 245: 56–63. arXiv:1406.4677. Bibcode:2015Icar..245...56S. doi:10.1016/j.icarus.2014.09.023. S2CID 119248574.
  7. ^ a b c d 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.
  8. ^ a b c d e f g h i Pravec, Petr; Sarounová, Lenka; Rabinowitz, David L.; Hicks, Michael D.; Wolf, Marek; Krugly, Yurij N.; et al. (July 2000). "Two-Period Lightcurves of 1996 FG 3, 1998 PG, and (5407) 1992 AX: One Probable and Two Possible Binary Asteroids". Icarus. 146 (1): 190–203. Bibcode:2000Icar..146..190P. doi:10.1006/icar.2000.6375.
  9. ^ a b c d e f Wolters, Stephen D.; Rozitis, Ben; Duddy, Samuel R.; Lowry, Stephen C.; Green, Simon F.; Snodgrass, Colin; et al. (December 2011). "Physical characterization of low delta-V asteroid (175706) 1996 FG3". Monthly Notices of the Royal Astronomical Society. 418 (2): 1246–1257. Bibcode:2011MNRAS.418.1246W. doi:10.1111/j.1365-2966.2011.19575.x.
  10. ^ a b c d Mueller, Michael; Delbo', M.; Hora, J. L.; Trilling, D. E.; Bhattacharya, B.; Bottke, W. F.; et al. (April 2011). "ExploreNEOs. III. Physical Characterization of 65 Potential Spacecraft Target Asteroids" (PDF). The Astronomical Journal. 141 (4): 9. Bibcode:2011AJ....141..109M. doi:10.1088/0004-6256/141/4/109.
  11. ^ a b c d e f g h i j Walsh, Kevin J.; Delbo', Marco; Mueller, Michael; Binzel, Richard P.; DeMeo, Francesca E. (April 2012). "Physical Characterization and Origin of Binary Near-Earth Asteroid (175706) 1996 FG3". The Astrophysical Journal. 748 (2): 7. arXiv:1203.4820. Bibcode:2012ApJ...748..104W. doi:10.1088/0004-637X/748/2/104. S2CID 62800879.
  12. ^ a b Pravec, P.; Scheirich, P.; Kusnirák, P.; Sarounová, L.; Mottola, S.; Hahn, G.; et al. (March 2006). "Photometric survey of binary near-Earth asteroids". Icarus. 181 (1): 63–93. Bibcode:2006Icar..181...63P. doi:10.1016/j.icarus.2005.10.014.
  13. ^ 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.
  14. ^ a b c "LCDB Data for (175706)". Asteroid Lightcurve Database (LCDB). Retrieved 14 December 2016.
  15. ^ a b Thomas, Cristina A.; Emery, Joshua P.; Trilling, David E.; Delbó, Marco; Hora, Joseph L.; Mueller, Michael (January 2014). "Physical characterization of Warm Spitzer-observed near-Earth objects". Icarus. 228: 217–246. arXiv:1310.2000. Bibcode:2014Icar..228..217T. doi:10.1016/j.icarus.2013.10.004. S2CID 119278697.
  16. ^ Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026.
  17. ^ New SIMPLEx Mission to Send SmallSats on Longest Deep Space Journey to Date at NASA
  18. ^ a b c Yu Fei (7 March 2017). "Riding an asteroid: China's next space goal". Xinhua News. Retrieved 1 May 2017.
  19. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 24 February 2018.
  20. ^ Mottola, Stefano; Lahulla, Felix (August 2000). "Mutual Eclipse Events in Asteroidal Binary System 1996 FG 3: Observations and a Numerical Model". Icarus. 146 (2): 556–567. Bibcode:2000Icar..146..556M. doi:10.1006/icar.2000.6421.
  21. ^ a b de León, J.; Mothé-Diniz, T.; Licandro, J.; Pinilla-Alonso, N.; Campins, H. (June 2011). "New observations of asteroid (175706) 1996 FG3, primary target of the ESA Marco Polo-R mission" (PDF). Astronomy and Astrophysics. 530: 4. Bibcode:2011A&A...530L..12D. doi:10.1051/0004-6361/201117041. Retrieved 14 December 2016.
  22. ^ New SIMPLEx Mission to Send SmallSats on Longest Deep Space Journey to Date at NASA

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