(192642) 1999 RD32

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(192642) 1999 RD32
1999rd32.jpg
Goldstone radar image showing the two lobes of suspected contact binary 1999 RD32.
Discovery[1]
Discovered by LINEAR (704)
Discovery date 8 September 1999
Designations
MPC designation (192642) 1999 RD32
Minor planet category Apollo NEO,
PHA[2]
Orbital characteristics[2]
Epoch 2014-May-23
(Uncertainty=0)[2]
Aphelion 4.677 AU (Q)
Perihelion 0.6083 AU (q)
2.643 AU (a)
Eccentricity 0.7698
4.30 yr
173.8° (M)
Inclination 6.793°
310.1°
299.9°
Physical characteristics
Dimensions ~5 kilometers (3 mi)[3]
17.08 hr[2][4][3]
Albedo ~0.04[3]
16.3[2]

(192642) 1999 RD32, provisionally known as 1999 RD32, is a near-Earth asteroid and potentially hazardous object.[2] It was discovered on 8 September 1999 by Lincoln Near-Earth Asteroid Research (LINEAR) at an apparent magnitude of 18 using a 1.0-meter (39 in) reflecting telescope.[1]

With two precovery images from January 1995,[5] the asteroid has a very well determined orbit with an observation arc of 17 years.[2] It is known that 1999 RD32 passed 0.0093 AU (1,390,000 km; 860,000 mi) from Earth on 27 August 1969.[6] During the 1969 close approach the asteroid reached about apparent magnitude 8.8.[7] The similarly-sized 4179 Toutatis also reached that brightness in September 2004. 1999 RD32 passed less than 0.007 AU (1,000,000 km; 650,000 mi) from asteroid 29 Amphitrite on 17 January 1939.[2]

Arecibo radar observations on 5-6 March 2012 showed that 1999 RD32 is approximately 5 kilometers (3 mi) in diameter[3] and has an albedo of only a few percent.[3] The two visible lobes suggest that 1999 RD32 is a tight binary asteroid or contact binary.[3] About 10–15% of near-Earth asteroids larger than 200 meters are expected to be contact binary asteroids with two lobes in mutual contact.[8]

Close-approaches to Earth[6]
Date Distance from Earth
1969-08-27 0.0093 AU (1,390,000 km; 860,000 mi)
2012-03-14 0.1487 AU (22,250,000 km; 13,820,000 mi)
2042-03-11 0.1428 AU (21,360,000 km; 13,270,000 mi)
2046-09-04 0.1071 AU (16,020,000 km; 9,960,000 mi)

References[edit]

  1. ^ a b "MPEC 1999-R32 : 1999 RD32". IAU Minor Planet Center. 1999-09-11. Retrieved 2014-02-28.  (J99R32D)
  2. ^ a b c d e f g h "JPL Small-Body Database Browser: 192642 (1999 RD32)". Jet Propulsion Laboratory. 2012-11-03 last obs (arc=17.8 years). Retrieved 2014-02-28. 
  3. ^ a b c d e f "(192642) 1999 RD32 Goldstone Radar Observations Planning". NASA/JPL Asteroid Radar Research. 2012-03-12. Retrieved 2014-02-28. 
  4. ^ Warner, Brian D.; Megna, Ralph (2012). "Lightcurve Analysis of NEA (192642) 1999 RD32". The Minor Planet Bulletin 39 (3): 154. Bibcode:2012MPBu...39..154W. 
  5. ^ "(192642) = 1999 RD32 Orbit". Minor Planet Center. 2012-11-03 (arc=6515 days). Retrieved 2014-02-28. 
  6. ^ a b "JPL Close-Approach Data: 192642 (1999 RD32)". 2012-11-03 last obs (arc=17.8 years). Retrieved 2014-02-28. 
  7. ^ "1999RD32 Ephemerides for 25 August 1969 through 31 August 1969". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 2014-02-28. 
  8. ^ Michael Busch (2012-03-12). "Near-Earth Asteroids and Radar Speckle Tracking". Retrieved 2014-02-28. 

External links[edit]