2005 HC4

Asteroid June 2017 yes #FFC2E0 2005 HC 4 Orbit of 2005 HC4.gif LONEOS 30 April 2005 Mercury Crosser Venus Crosser Apollo Asteroid Mars Crosser 3 May 2005 (JD 2453493.5) 1.8207 AU Gm on 0.070657 AU Gm on 3.5707 AU Gm on on 0.96119 2.46 yr (897.30 d) 8.3967° 63.790° 309.01° 341.42° 210–480 m 20.7 0.40120 ms /day 9 0.0615074 AU Gm on 1.92798 AU Gm on 2005 HC4 is the asteroid with the second-smallest perihelion and the asteroid with the smallest known perihelion of any known object orbiting the Sun from 2005 to 2024 (except sungrazing comets). Its extreme orbital eccentricity brings it to within 0.071 AU of the Sun (23% of Mercury's perihelion) and takes it as far as 3.562 AU from the Sun (well beyond the orbit of Mars).IAU Minor Planet Center https://minorplanetcenter.net/db_search/show_object?object_id=2005+HC4 2026-01-12 minorplanetcenter.net Since then, another asteroid, 2024 YL 3, has been found to have a closer perihelion, at about 0.070 AU.IAU Minor Planet Center https://minorplanetcenter.net/db_search/show_object?object_id=2024+YL3 2026-01-12 minorplanetcenter.net Due to its very small perihelion and comparably large aphelion, 2005 HC 4 achieves the fastest speed of any known asteroid bound to the Solar System with a velocity of 157 km/s (565,000 km/h; 351,000 mi/h) at perihelionAs calculated with the vis-viva-equation : where: v is the relative speed of the two bodies r is the distance between the two bodies a is the semi-major axis (a > 0 for ellipses, a = ∞ or 1/a = 0 for parabolas, and a < 0 for hyperbolas) G is the gravitational constant M is the mass of the central body (there are comets, however, which obtain much higher speeds). See also List of Mercury-crossing minor planets List of Venus-crossing minor planets Apollo asteroids List of Mars-crossing minor planets References 2005-05-11 last obs (arc=11 days) JPL Small-Body Database Browser: (2005 HC4) http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2005%20HC4 Jet Propulsion Laboratory 30 March 2016 MPEC 2005-J02 : 2005 HC4 IAU Minor Planet Center 2005-05-01 http://www.minorplanetcenter.org/mpec/K05/K05J02.html 2014-03-05 (K05H04C) NEODyS 2005 HC4 Near Earth Objects Dynamic Site https://newton.spacedys.com/neodys/index.php?pc=1.1.9&n=2005HC4 2014-03-07 External links 2005+HC4 2005HC4 # Category:Minor planet object articles (unnumbered) Category:Mercury-crossing asteroids Category:Venus-crossing asteroids 20050430