2004 FU162 is an Atennear-Earth asteroid less than 20 meters in diameter crudely estimated to have passed roughly 6500 km above the surface of Earth[b] on 31 March 2004.
On 31 March 2004, around 15:35 UTC, the asteroid is crudely estimated to have passed within approximately 1 Earth radius (R🜨) or 6,400 kilometers of the surface of the Earth (or 2.02 R🜨 from Earth's center). But due to the very short observation arc, the uncertainty in the close approach distance is a large ±15000 km. By comparison, geostationary satellites orbit at 5.6 R🜨 and GPS satellites orbit at 3.17 R🜨 from the center of the Earth.
It was only observed four times in the space of 44 minutes and could not be followed up. Nevertheless, "the orbit is quite determinate and, given the exceptional nature of this close approach, the object is now receiving a designation".[3] No precovery images have been found.
2004 FU162 is estimated to be approximately 6 meters in diameter.[citation needed] This means that it would burn up from atmospheric friction before striking the ground in the case of an Earth impact.
On 26 March 2010, it may have come within 0.0825 AU (12.3 million km) of Earth,[4] but with an uncertainty parameter of 9,[1] the orbit is poorly determined.
Another, larger near-Earth asteroid, 2004 FH passed just two weeks prior to 2004 FU162.
A closer non-impacting approach to Earth was not known until 2008 TS26 on 9 October 2008.
See also
Closest non-impacting asteroids to Earth, except Earth-grazing fireballs (using JPL SBDB numbers and Earth radius of 6,378 km)