(6178) 1986 DA

(6178) 1986 DA
Discovery [1]
Discovered by M. Kizawa
Discovery site Shizuoka
Discovery date 16 February 1986
Designations
MPC designation (6178) 1986 DA
1986 DA
Amor · NEO
Orbital characteristics [1]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0
Observation arc 38.03 yr (13,890 days)
Aphelion 4.4646 AU
Perihelion 1.1803 AU
2.8224 AU
Eccentricity 0.5817
4.74 yr (1,732 days)
108.58°
Inclination 4.3046°
64.663°
127.31°
Earth MOID 0.1904 AU
Physical characteristics
Dimensions 3.149 km[2]
3.199±0.207 km[3]
3.15 km (taken)[4]
2.3 km[1]
3.50 h[5][lower-alpha 1]
3.51 h[6]
0.15[1]
0.0778[2]
0.161±0.034[3]
B–V = 0.677
U–B = 0.267
M [4]
15.1[1][3]
15.9[2][4]
16.11[6]

    (6178) 1986 DA is an unnamed, metallic asteroid, classified as near-Earth object and Amor asteroid, about 3 kilometers in diameter. It was discovered on 16 February 1986, by Japanese astronomer Minoru Kizawa at the Nihondaira Observatory in Shimizu, Japan.[7]

    The asteroid orbits the Sun at a distance of 1.2–4.5 AU once every 4 years and 9 months (1,732 days). Its orbit shows an eccentricity of 0.58 and an inclination of 4 degrees from the plane of the ecliptic.[1] As an Amor asteroid, it approaches the orbit of Earth from the outside but does not cross it. It crosses however the orbit of Mars and can be classified as a Mars-crosser.

    It was most probably formed from a larger body through a catastrophic collision with another object. Radar measurements of this body indicate that the surface is relatively smooth on scales of less than a meter, but it is highly irregular on scales of 10–100 meters. Several light-curve analysis gave it a concurring rotation period of 3.50 to 3.51 hours with a relatively high brightness amplitude between 0.03 and 0.48 in magnitude, indicating an irregular shape.[5][lower-alpha 1][6]

    The metallic M-type asteroid is notable for being significantly more radar-reflective than other asteroids. Radar measurements suggest it is composed of nickel and iron and that it was derived from the center of a much larger object that experienced melting and differentiation. The observed radar albedo was 0.58 and the optical albedo was 0.14.[8] According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid has an albedo of 0.08 and 0.16, and a diameter of 3.1 to 3.2 kilometers, respectively.[2][3] The Collaborative Asteroid Lightcurve Link selects 3.15 kilometers as best result, while the JPL-website lists an outdated diameter estimate of 2.3 kilometers.[1]

    The asteroid achieved its most notable recognition when scientists revealed that it contained over "10,000 tons of gold and 100,000 tons of platinum", or an approximate value at the time of its discovery of "$90 billion for the gold and a cool trillion dollars for the platinum, plus loose change for the asteroid's 10 billion tons of iron and a billion tons of nickel."[9] In 2012 the estimated value of 100,000 tons of platinum was worth approximately five trillion US dollars. The delta-v for a spacecraft rendezvous with this asteroid from low earth orbit is 7.1 km/s.[10]

    References

    1. 1 2 Pravec (1999) web: rotation period 3.50 hours with a brightness amplitude of 0.3 mag. H = 15.4. No LCDB quality code assigned. No lightcurve published (note: "N"). Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (6178)
    1. 1 2 3 4 5 6 7 "JPL Small-Body Database Browser: 6178 (1986 DA)" (2015-07-28 last obs.). Jet Propulsion Laboratory. Retrieved February 2016.
    2. 1 2 3 4 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. Retrieved February 2016.
    3. 1 2 3 4 Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved February 2016.
    4. 1 2 3 "LCDB Data for (6178)". Asteroid Lightcurve Database (LCDB). Retrieved February 2016.
    5. 1 2 Zeigler, K. W. (March 1990). "Photoelectric Photometry of Asteroids 81 Terpsichore, 381 Myrrha, and 1986 DA". The Minor Planet Bulletin 17.: 1. Bibcode:1990MPBu...17....1Z. Retrieved February 2016.
    6. 1 2 3 Wisniewski, W. Z. (June 1987). "Photometry of six radar target asteroids". Icarus: 566–572. Bibcode:1987Icar...70..566W. doi:10.1016/0019-1035(87)90096-0. ISSN 0019-1035. Retrieved February 2016.
    7. ↑ "6178 (1986 DA)". Minor Planet Center. Retrieved February 2016.
    8. ↑ Ostro, S. J.; Rosema, K. D.; Campbell, D. B.; Chandler, J. F.; Hine, A. A.; Hudson, R. S. (June 1991). "Asteroid 1986 DA - Radar evidence for a metallic composition". Science: 1399–1404.NASA–supportedresearch.(SciHomepage). Bibcode:1991Sci...252.1399O. doi:10.1126/science.252.5011.1399. ISSN 0036-8075. Retrieved February 2016.
    9. ↑ Ostro, Steven J.; Campbell, D. B.; Chandler, J. F.; Hine, A. A.; Hudson, R. S.; Rosema, K. D.; et al. (October 1991). "Asteroid 1986 DA: Radar evidence for a metallic composition". In NASA. Bibcode:1991plas.rept..174O. Retrieved February 2016.
    10. ↑ "Delta-v for spacecraft rendezvous with all known near-Earth asteroids". NASA. 2006-06-01. Retrieved 2006-06-08.

    External links

    This article is issued from Wikipedia - version of the Wednesday, May 04, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.