2004 FU162 is an Aten near-Earth asteroid less than 20 meters in diameter crudely estimated to have passed roughly 6500 km above the surface of Earth on 31 March 2004.

It was only observed for 44 minutes on 31 March 2004, by the Lincoln Near-Earth Asteroid Research (LINEAR) team at Lincoln Laboratory's Experimental Test Site in Socorro, New Mexico, and remains a lost asteroid. The estimated 4 to 6 meter sized body made one of the closest known approaches to Earth.

Description

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.

As of 2008[update] this was the third or fourth closest approach. The first observation of 2004 FU162 was not announced until 22 August 2004.

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". 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, but with an uncertainty parameter of 9, 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)
AsteroidDateDistance from surface of EarthUncertainty in approach distanceObservation arcReference
2025 UC112025-10-30 12:11237 km±11 km1 day (41 obs)
2020 VT42020-11-13 17:21368 km±11 km5 days (34 obs)
2020 QG2020-08-16 04:092939 km±11 km2 days (35 obs)
2021 UA12021-10-25 03:073049 km±10 km1 day (22 obs)
2023 BU2023-01-27 00:293589 km±<1 km10 days (231 obs)
2011 CQ12011-02-04 19:395474 km±5 km1 day (35 obs)
2019 UN132019-10-31 14:456235 km±189 km1 day (16 obs)
2008 TS262008-10-09 03:306260 km±970 km1 day (19 obs)
2004 FU1622004-03-31 15:356535 km±13000 km1 day (4 obs)

Notes

External links