(276033) 2002 AJ129, provisional designation 2002 AJ129, is a Mercury-crossing asteroid. It has the ninth-smallest perihelion of all numbered asteroids, after asteroids such as 2000 BD19, 2004 UL, and 2008 XM.[6] It makes close approaches to all of the inner planets[3] and asteroid 4 Vesta.[7] The asteroid is estimated to be between 0.5–1.2 kilometers (0.3–0.7 mi) across.[5] In January 2018 there was much media hype about this asteroid being classified as a potentially hazardous asteroid, although there is no known threat of an impact for hundreds if not thousands of years. The media has compared the size of the asteroid to the Burj Khalifa in Dubai.[8]
On 4 February 2018 at 21:31 UT, the asteroid passed about 0.028126 AU (4,207,600 km; 2,614,500 mi) from Earth.[3][10] The 2018 Earth approach distance was known with a 3-sigma accuracy of ±200 km.[3]Goldstone is scheduled to observe the asteroid from 3 to 6 February.[11] By 4 February 2018 11:00 UT, the asteroid brightened to apparent magnitude 14 and had a solar elongation of more than 100°.[12]
2172 approach
On 8 February 2172, the asteroid will pass about 0.00458 AU (685,000 km; 426,000 mi) from Earth.[3] The 2172 Earth approach distance is known with a 3-sigma accuracy of ±4000 km.
As we look even further into the future the known trajectory becomes more divergent. By the Earth approach of 0.24 AU (36,000,000 km; 22,000,000 mi) on 19 February 2196 the uncertainty increases to ±2.4 million km.[3]
History of close approaches of large near-Earth objects since 1908 (A)
(A) This list includes near-Earth approaches of less than 2 lunar distances (LD) of objects with H brighter than 20. (B)Nominal geocentric distance from the center of Earth to the center of the object (Earth has a radius of approximately 6,400 km). (C) Diameter: estimated, theoretical mean-diameter based on H and albedo range between X and Y. (D) Reference: data source from the JPL SBDB, with AU converted into LD (1 AU≈390 LD) (E) Color codes: unobserved at close approach observed during close approach upcoming approaches