(23187) 2000 PN9

Near-Earth asteroid November 2025 yes (23187) 2000 PN 9 #FFC2E0 8 August 2000 Lincoln Near-Earth Asteroid Research (LINEAR) Lincoln Laboratory Experimental Test Site (23187) 2000 PN 9 NEOApolloPHA 21 November 2025 (JD 2461000.5) 0 2.93547 AU 0.758421 AU 1.84695 AU 0.589365 51.3359° 164.281° 293.541° 324.539° 2.51009 y (916.812 d) 0.392665° / d 0.014953 AU 3.419 0.855 0.035 km4589Given as an equatorial diameter of 1.71 0.07 km 1.82 0.08 × 1.82 0.07 × 1.77 0.11 km4589 16.05 2.53216 0.00015 h4589 30 17°4589 96 36°4589 Sq-type or Q-type4591 (23187) 2000 PN 9 is an unnamed near-Earth asteroid (NEA) on a highly inclined orbit. An Apollo asteroid, it was discovered on 8 August 2000 by the Lincoln Near-Earth Asteroid Research (LINEAR) program. It is around 1.7 km mi in size and shaped like a top, though its equatorial ridge is less prominent compared to other top-shaped asteroids. History 2000 PN 9 was discovered on 8 August 2000 by the Lincoln Near-Earth Asteroid Research (LINEAR) program from the Lincoln Laboratory Experimental Test Site in Socorro, New Mexico, United States. It was given its provisional designation of 2000 PN 9 by the Minor Planet Center (MPC), and its discovery was announced in a Minor Planet Electronic Circular on 30 August. Once its orbit was sufficiently determined, the MPC numbered it (23187) on 9 March 2001.112 2025, it has not yet been given a name. Orbit 2000 PN 9 orbits the Sun at an average distance—its semi-major axis—of 1.85 astronomical units (AU), taking 2.51 years to complete one revolution. Along its orbit, its distance from the Sun varies between 0.75 AU at perihelion to 2.94 AU at aphelion due to its orbital eccentricity of 0.59. Its orbit is inclined by 51.34° with respect to the ecliptic plane. It is a near-Earth asteroid (NEA) and an Apollo asteroid, since its orbit crosses Earth's and its semi-major axis is greater than one AU. It makes periodic close approaches to Earth, categorizing it as a potentially hazardous asteroid.167 Physical characteristics 2000 PN 9 is 1.71 km mi in size and shaped like a top or diamond, characteristic of rubble pile asteroids. It is nearly spherical, with a less pronounced equatorial ridge compared to other top-shaped NEAs.4589, 4592 Based on its surface spectrum, it is classified as an Sq-type or Q-type asteroid. It has no known moons.4591 Based on observations of 2000 PN 9's lightcurve, or variations in its observed brightness, it has a rotation period of 2.53 hours, rotating in a prograde direction.4589 Its rapid rotation means that its surface likely experiences frequent landslides and mass shedding events that move regolith from its polar regions to its equator. This process exposes unweathered material, and its Sq/Q-type classification could be a consequence of these processes. However, its lack of a satellite is unusual as many top-shaped NEAs have moons; it is one of the largest solitary top-shaped asteroids known.4591 The YORP effect can spin up an NEA towards the spin barrier, at which point a cohesionless rubble pile would break up due to centrifugal forces. Material flung out can then reaccrete, forming a multiple asteroid system. 2000 PN 9 lies close to the spin barrier, which is around 2.2 hours, but its rotation is not being spun up. Its symmetrical shape means that it has not experienced breakup in the past. This indicates that it may be trapped in a state of rotational equilibrium, where the torque produced by the YORP effect enforces a steady rotation period instead.4592 Notes References 2025-11-12 last obs. JPL Small-Body Database Lookup: 23187 (2000 PN9) https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=23187 Jet Propulsion Laboratory 19 November 2025 (23187) = 2000 PN9 https://www.minorplanetcenter.net/db_search/show_object?object_id=23187 Minor Planet Center 19 November 2025 live (2300 obs) MPEC 2000-Q37 : 2000 PN9 https://minorplanetcenter.net/mpec/K00/K00Q37.html Minor Planet Center Staff Minor Planet Electronic Circular Minor Planet Center 2000MPEC....Q...37F 2000-Q37 30 August 2000 20 November 2025 M. P. C. 42217-42426 https://www.minorplanetcenter.net/iau/ECS/MPCArchive/2001/MPC_20010309.pdf Minor Planet Circulars Minor Planet Center 9 March 2001 42217-42426 20 November 2025 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 Francis Matthew R. What Tumbling Asteroids Tell Us About Their Innards 6 November 2025 Eos https://eos.org/articles/what-tumbling-asteroids-tell-us-about-their-innards 22 November 2025 Belskaya Irina N. Fornasier Sonia Krugly Yurij N. Polarimetry and BVRI photometry of the potentially hazardous near-Earth Asteroid (23187) 2000 PN 9 May 2009 Icarus 201 1 167–171 10.1016/j.icarus.2008.12.026 2009Icar..201..167B Dover L. Physical modelling of near-Earth asteroid (23187) 2000 PN9 with ground-based optical and radar observations November 2023 Monthly Notices of the Royal Astronomical Society 525 3 4581–4595 10.1093/mnras/stad2528 free 2308.09630 2023MNRAS.525.4581D External links 23187 23187 23187 23186 Knauss 23187 (23188) 2000 PJ20 Astronomy Outer Space 023187 023187 20000808 023187