(132524) 2002 JF56

132524 APL
132524 APL New Horizons.jpg
APL seen by New Horizons from 1.3 million kilometers in June 2006
Discovered byLINEAR
Discovery siteLincoln Lab ETS
Discovery date9 May 2002
(132524) APL
Named after
Applied Physics Laboratory
2002 JF56
main-belt[1][2] · (middle)
Orbital characteristics[2]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 0
Observation arc27.41 yr (10,012 d)
Aphelion3.3163 AU
Perihelion1.8904 AU
2.6033 AU
4.20 yr (1,534 d)
0° 14m 4.56s / day
Physical characteristics
Mean diameter
2.5 km[5]

132524 APL, provisional designation 2002 JF56, is a small background asteroid in the intermediate asteroid belt. It was discovered by LINEAR in May 2002,[1] and imaged by the New Horizons space probe on its flyby in June 2006, when it was passing through the asteroid belt. The stony S-type asteroid measures approximately 2.5 kilometers (1.6 miles) in diameter.[5][6]

Discovery and classification[]

APL was discovered on 9 May 2002 by astronomers of the Lincoln Near-Earth Asteroid Research (LINEAR) at the Lincoln Laboratory's ETS near Socorro, New Mexico, United States.[2] It is a non-family asteroid from the main belt's background population,[3][4] and orbits the Sun in the central asteroid belt at a distance of 1.9–3.3 AU once every 4 years and 2 months (1,534 days; semi-major axis of 2.6 AU). Its orbit has an eccentricity of 0.27 and an inclination of 4° with respect to the ecliptic.[2]


Alan Stern, principal investigator for New Horizons, named the asteroid in reference to the Johns Hopkins University Applied Physics Laboratory (APL), which developed the New Horizons, NEAR Shoemaker and MESSENGER missions.[1][7] The official naming citation was published by the Minor Planet Center on 6 January 2007 (M.P.C. 58598).[8]

New Horizons fly by[]

Top and bottom images of APL taken by Ralph at 1.34 and 3.36 million kilometers, respectively
Animation of New Horizons's trajectory from 19 January 2006 to 30 December 2030
  Pluto ·   Arrokoth ·   Earth
  APL ·   Jupiter ·    New Horizons

The New Horizons probe flew by it at a distance of approximately 102,000 kilometers on 13 June 2006. At its closest it was about 14 of a lunar distance away from the asteroid. The flyby was incidental, and not all the instruments were online at this time; they were still being activated after the spacecraft's launch on January 19, 2006.[7][9] This is why the spacecraft's reconnaissance imager, and highest magnification telescope was not online yet at the time of the flyby.[5]

Ralph instrument[]

APL was imaged with the 75-millimeter Ralph telescope, but not with the designed reconnaissance imager LORRI because it was not turned on yet.[5] LORRI was not activated until 29 August 2006 when its cover was opened and its first light image would be Messier 7.[10] It was in general possible to capitalize on the target of opportunity, and the asteroid was tracked for several days in June 2006 in addition to the other tests.[5] In March, New Horizons had passed the orbit of Mars, and the spacecraft was undergoing various course correction maneuvers and tests throughout this time; as mentioned LORRI was not activated for another couple months.[5] New Horizons passed through the asteroid belt during the summer of 2006, and the test helped prepare the team and spacecraft for the future flybys of Jupiter and Pluto.[11] The asteroid belt is a feature of the Solar System, consisting of a large number asteroids that orbit the sun primarily between 2.2 and 3.2 AU (Earth-Sun distance) which is between the orbits of planets Mars and Jupiter.[12]

Traversing the asteroid belt[]

Crossing the asteroid belt is possible, because although there are over a million asteroids larger than 1 km in diameter, the distance between them is so large spacecraft pass through empty space. This was established in the early 1970s when Pioneer 10 and Pioneer 11 traversed the belt for the first time. There is some increased probability of encountering dust, but otherwise it takes special planning to actually pass very close to an asteroid as was done with Galileo spacecraft. In the 1990s, when it passed through the belt on its way to its second Earth gravity assist, it flew by 951 Gaspra; after the flyby en route to Jupiter, it flew by 243 Ida and discovered its moon Dactyl.[13]

Physical characteristics[]

Prior and in support of the New Horizons fly by on 13 June 2006, astronomers at ESO's Paranal Observatory were observing APL with one of the four 8.2-meter Very Large Telescopes (UT1, Antu) between 25 May and 2 June 2006. The astronomers found, that APL has a spectral type of a common, stony S-type asteroid.[6] Using the Ralph instrument (see above), New Horizons was later able to estimate a diameter of approximately 2.5 kilometers (1.6 miles) for the asteroid.[5]

See also[]


  1. ^ a b c d e "132524 APL (2002 JF56)". Minor Planet Center. Retrieved 4 December 2018.
  2. ^ a b c d e "JPL Small-Body Database Browser: 132524 APL (2002 JF56)" (2018-02-25 last obs.). Jet Propulsion Laboratory. Retrieved 4 December 2018.
  3. ^ a b "Asteroid 132524 APL". Small Bodies Data Ferret. Retrieved 4 December 2018.
  4. ^ a b "Asteroid (145534) Jhongda". AstDyS-2, Asteroids – Dynamic Site. Retrieved 4 December 2018.
  5. ^ a b c d e f g "New Horizons Mission to Pluto". Technology Org. 18 July 2015. Retrieved 4 December 2018.
  6. ^ a b c "Electronic Telegram No. 547". International Astronomical UnionCentral Bureau for Astronomical Telegrams. 16 June 2006. Retrieved 4 December 2018.
  7. ^ a b Buckley, Michael (5 March 2007). "APL Rocks! Asteroid Named After JHU Applied Physics Lab". The JHU Gazette. Retrieved 4 December 2018.
  8. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 December 2018.
  9. ^ Talbert, Tricia (25 March 2015). "New Horizons Launch Information". NASA. Retrieved 3 January 2019.
  10. ^ "New Horizons – Pluto-Bound Camera Sees 'First Light'". pluto.jhuapl.edu. 1 September 2006. Retrieved 4 December 2018.
  11. ^ Chris Gebhardt (12 July 2015). "New Horizons – Pluto-Bound Camera Sees 'First Light'". www.nasaspaceflight.com. Retrieved 4 December 2018.
  12. ^ "Asteroid Belt Facts – Interesting Facts about the Asteroid Belt". Space Facts. 11 September 2014. Retrieved 4 December 2018.
  13. ^ "In science fiction movies, the "asteroid belt" is always pictured as a very crowded place. How dense is it really: impossible to navigate, risky or just interesting?". Scientific American. 5 August 1997. Retrieved 4 December 2018.

Further reading[]

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