1999 SF10

1999 SF10
Discovery[1][a]
Discovery date30 September 1999 (Initial reported obs.)
Designations
1999 SF10
NEO · Apollo
Orbital characteristics[2]
Epoch 21 November 2025 (JD 2461000.5)
Uncertainty parameter 0
Aphelion1.6039 AU
Perihelion0.9550 AU
1.2795 AU
Eccentricity0.2536
1.4473 y (528.62 d)
1.251°
0.6810° / d
Inclination1.2081°
25.817°
27.975°
Earth MOID0.0038 AU
TJupiter5.026
Physical characteristics
Dimensions85 m × 55 m[3]: 150 
60 m
2.4663±0.0005[4]: 481 
0.117[3]: 150 
24.46[2]

1999 SF10 is a small, quickly rotating unnamed near-Earth asteroid (NEA). First observed on 30 September 1999 by the Lincoln Near-Earth Asteroid Research (LINEAR) program in Socorro, New Mexico, United States, it is an Earth-crossing Apollo asteroid. Its diameter is estimated to be around 60 metres (200 ft) in size with a very rapid rotation period of 2.47 minutes, indicating that it is a monolithic object.

History

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1999 SF10 was first observed on 30 September 1999 by the Lincoln Near-Earth Asteroid Research (LINEAR) program from its Experimental Test Site (ETS) in Socorro, New Mexico, United States.[1] It was given the provisional designation 1999 SF10 by the Minor Planet Center (MPC), and its detection was announced in a Minor Planet Electronic Circular on 4 October 1999.[5] At the time of its first observation, it was rapidly approaching Earth, and on 12 October it passed within a distance of 0.0076 astronomical units (AU; 3.0 LD).[4]: 481 

As of 2025, it has not been numbered or named by the MPC.[2] It also has not been formally assigned a discoverer, which will happen when it is numbered.[1]

Orbit

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Diagram showing 1999 SF10's orbit in the inner Solar System. The ecliptic grid is shown.

1999 SF10 is classified as a near-Earth asteroid (NEA). It orbits the Sun at an average distance—its semi-major axis—of 1.28 AU, taking 1.45 years to complete one revolution. It has a low orbital inclination of 1.45° relative to the ecliptic plane. Along its orbit, its distance from the Sun varies between 0.96 AU at perihelion to 1.60 AU at aphelion due to its orbital eccentricity of 0.25.[2] Because its perihelion lies below 1 AU, it is also classified as an Earth-crossing Apollo asteroid.[6][2]

Physical characteristics

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1999 SF10 has an estimated mean diameter of 60 metres (200 ft) with dimensions of 85 by 55 metres (279 ft × 180 ft), assuming a geometric albedo of 0.110–0.117; its estimated size may be off by a factor of 2.[4]: 481 [3]: 150  Observations of its lightcurve, or variations in its observed brightness, suggest that it has a rotation period of 2.47 minutes,[4]: 481  classifying it as a monolithic fast-rotating asteroid (MFRA).[3]: 150  MFRAs have rotation periods much faster than those typically observed in asteroids, rotating faster than the critical period below which a strengthless body will self-destruct due to centrifugal forces.[3]: 148 

See also

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Notes

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  1. ^ Discoverer not yet assigned by the MPC

References

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  1. ^ a b c "1999 SF10". Minor Planet Center. Retrieved 11 November 2025.{{cite web}}: CS1 maint: url-status (link) (67 obs)
  2. ^ a b c d e "JPL Small-Body Database Lookup: (1999 SF10)" (2025-09-12 last obs.). Jet Propulsion Laboratory. Retrieved 11 November 2025.{{cite web}}: CS1 maint: url-status (link)
  3. ^ a b c d e Whiteley, Robert J.; Tholen, David J.; Hergenrother, Carl W. (May 2002). "Lightcurve Analysis of Four New Monolithic Fast-Rotating Asteroids". Icarus. 157 (1): 139–154. Bibcode:2002Icar..157..139W. doi:10.1006/icar.2001.6796.
  4. ^ a b c d Pravec, Petr; Hergenrother, Carl; Whitely, Rob; Šarounová, Lenka; Kušnirák, Peter; Wolf, Marek (October 2000). "Fast Rotating Asteroids 1999 TY2, 1999 SF10, and 1998 WB2". Icarus. 147 (2): 477–486. Bibcode:2000Icar..147..477P. doi:10.1006/icar.2000.6458.
  5. ^ Minor Planet Center Staff (4 October 1999). "MPEC 1999-T14 : 1999 SF10". Minor Planet Electronic Circular. 1999-T14. Minor Planet Center. Retrieved 11 November 2025.{{cite journal}}: CS1 maint: url-status (link)
  6. ^ "NEO Groups". NASA/JPL Near-Earth Object Program Office. Archived from the original on 2 February 2002. Retrieved 4 June 2012.
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