2004 FH

Infobox Planet | discovery=yes | physical_characteristics = yes | bgcolour=#FFFFC0
name=2004 FH

discoverer=LINEAR
discovered=March 15, 2004
alt_names="none"
mp_category=Aten asteroid,
Earth-crosser asteroid
Venus-crosser asteroid
epoch=July 14, 2004 (JD 2453200.5)
semimajor=122.360 Gm (0.818 AU)
perihelion=87.070 Gm (0.582 AU)
aphelion=157.651 Gm (1.054 AU)
eccentricity=0.288
period=270.192 d (0.740 a)
inclination=0.016 62°
asc_node=264.432°
arg_peri=62.952°
mean_anomaly=28.042°
avg_speed=32.237 km/s
dimensions=0.030 km
mass=2.8×10⁷ kg
density=2 ? g/cm³
surface_grav=8.4×10^-6 m/s²
escape_velocity=16×10^-6 km/s
rotation=? d
spectral_type=?
abs_magnitude=26.42
albedo=0.1 ?
single_temperature=~308 K

2004 FH is a near-Earth asteroid that was discovered on March 15, 2004 by the NASA-funded LINEAR asteroid survey. The object is roughly 30 metres in diameter and passed just 43,000 km (26,000 miles) above the Earth's surface on March 18, 2004 at 22:08 UTC; making it the fourth or fifth closest approach to Earth recorded as of 2006 (see the diagram below). For comparison, geostationary satellites orbit Earth at 35,790 km.

2004 FH is an Aten family asteroid, although by some definitions it should be called a meteoroid, since it is smaller than 50 metres in diameter. Had this object hit Earth, it would probably have detonated high in the atmosphere. It might have produced a blast measured in hundreds of kilotons of TNT, but may not have produced any ground level effect. Despite its relatively small size (about 30 metres), it is still the third largest asteroid detected coming closer to the Earth than the Moon.

The asteroid will not make another close approach to Earth until 2044 when it will be no closer than 1.4 Gm (1.4 million kilometres). 2004 FH also has the distinction of having the lowest inclination of any known near-earth asteroids.

References

# Chesley, Steven R; Chodas, Paul W. [http://neo.jpl.nasa.gov/news/news142.html Recently Discovered Near-Earth Asteroid Makes Record-breaking Approach to Earth] . Pasadena, California (USA): "NASA Near Earth Object Program Office". March 17, 2004.

ee also

* Near-Earth object
* List of noteworthy asteroids
*

External links

* [http://www.cfa.harvard.edu/mpec/K04/K04F24.html MPEC 2004-F24]
* [http://www.klet.org/klenot//html/2004fh.html Images of 2004 FH]
* [http://neo.jpl.nasa.gov/news/news142.html Official press release by NASA]
* [http://www.space.com/scienceastronomy/asteroid_warning_040322.html "Asteroid Scare Prompts NASA to Formalize Response by Robert Roy Britt"]
* [http://www.cfa.harvard.edu/iau/lists/Closest.html Minor Planet Center: Closest Approaches to the Earth by Minor Planets]