1999 SF10

Near-Earth asteroid November 2025 yes 1999 SF 10 #FFC2E0 Discoverer not yet assigned by the MPC 30 September 1999 (Initial reported obs.) 1999 SF 10 NEOApollo 21 November 2025 (JD 2461000.5) 0 1.6039 AU 0.9550 AU 1.2795 AU 0.2536 1.2081° 25.817° 27.975° 1.251° 0.6810° / d 1.4473 y (528.62 d) 0.0038 AU 5.026 60 m 85 x 55 m150 2.4663 0.0005481 0.117150 24.46 1999 SF 10 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 m ft in size with a very rapid rotation period of 2.47 minutes, indicating that it is a monolithic object. History 1999 SF 10 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. It was given the provisional designation 1999 SF 10 by the Minor Planet Center (MPC), and its detection was announced in a Minor Planet Electronic Circular on 4 October 1999. 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).481 2025, it has not been numbered or named by the MPC. It also has not been formally assigned a discoverer, which will happen when it is numbered. Orbit thumb|left|Diagram showing 1999 SF 10's orbit in the inner Solar System. The ecliptic grid is shown. 1999 SF 10 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. Because its perihelion lies below 1 AU, it is also classified as an Earth-crossing Apollo asteroid. Physical characteristics 1999 SF 10 has an estimated mean diameter of 60 m ft with dimensions of 85 x 55 m ft, assuming a geometric albedo of 0.110–0.117; its estimated size may be off by a factor of 2.481150 Observations of its lightcurve, or variations in its observed brightness, suggest that it has a rotation period of 2.47 minutes,481 classifying it as a monolithic fast-rotating asteroid (MFRA).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.148 See also List of fast rotators (minor planets) Notes References 1999 SF10 https://www.minorplanetcenter.net/db_search/show_object?object_id=1999+SF10 Minor Planet Center 11 November 2025 live (67 obs) 2025-09-12 last obs. JPL Small-Body Database Lookup: (1999 SF10) https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1999%20SF10 Jet Propulsion Laboratory 11 November 2025 live MPEC 1999-T14 : 1999 SF10 https://www.minorplanetcenter.net/mpec/J99/J99T14.html Minor Planet Center Staff Minor Planet Electronic Circular Minor Planet Center 1999-T14 4 October 1999 11 November 2025 live NEO Groups NASA/JPL Near-Earth Object Program Office http://neo.jpl.nasa.gov/neo/groups.html https://web.archive.org/web/20020202160655/http://neo.jpl.nasa.gov/neo/groups.html dead 2002-02-02 2012-06-04 Pravec Petr Hergenrother Carl Whitely Rob Šarounová Lenka Kušnirák Peter Wolf Marek Fast Rotating Asteroids 1999 TY 2, 1999 SF 10, and 1998 WB 2 October 2000 Icarus 147 2 477–486 10.1006/icar.2000.6458 2000Icar..147..477P Whiteley Robert J. Tholen David J. Hergenrother Carl W. Lightcurve Analysis of Four New Monolithic Fast-Rotating Asteroids May 2002 Icarus 157 1 139–154 10.1006/icar.2001.6796 2002Icar..157..139W External links 1999SF10 1999SF10 1999 SF10 Astronomy Outer Space # 19990930 # Category:Minor planet object articles (unnumbered)