2004 FH
Asteroid 2004 FH |
|
---|---|
Properties of the orbit ( animation ) | |
Orbit type | Aten type |
Major semi-axis | 0.818 AU |
eccentricity | 0.289 |
Perihelion - aphelion | 0.581 AU - 1.054 AU |
Inclination of the orbit plane | 0.021 ° |
Sidereal period | 270 d 5 h |
Mean orbital velocity | 32.237 km / s |
Physical Properties | |
Medium diameter | 30 m |
Dimensions | approx. 2.8 × 10 7 | kg
Medium density | ? g / cm³ |
Rotation period | 3.02 min |
Absolute brightness | 26.42 mag |
history | |
Explorer | LINEAR |
Date of discovery | March 15, 2004 |
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items. |
2004 FH is an asteroid about 30 m in diameter. It was discovered on March 16, 2004 by the LINEAR sky surveillance in New Mexico , USA . It moves at a distance of 0.581 ( perihelion ) to 1.054 ( aphelion ) astronomical units , in 270 days and 5 hours around the sun , the orbital eccentricity is therefore 0.289. Its orbit is almost not inclined towards the ecliptic at 0.021 ° . 2004 FH rotates very quickly around its axis in about 3 minutes.
2004 FH passed the earth on March 18, 2004 at 22:08 UTC at a distance of only about 43,000 km (measured from the earth's surface) with a relative speed of 7.9 km / s. Measured from the center of the earth, this corresponds to 0.00035 AU or about four diameters of the earth. Of all currently known near-earth objects (NEO), only the even smaller 2004 FU 162 has come closer to the earth so far.
A collision with Earth could have caused severe regional devastation. One of the explanatory hypotheses of the Tunguska event , for example, assumes a body about 50 m in size that collided with the earth, which would be comparable to 2004 FH. Objects of this size are expected to pass the earth in such close proximity every two years, but 2004 FH is the first actually observed.
At the time of closest approach, the object with an apparent brightness of around 10 magnitudes was too dark to be seen with the naked eye.
In 2004, FH was practically unobservable from Germany with a telescope . In the south it was about 3 degrees above the horizon in the southern sky in the constellation Air Pump . In northern Germany, FH was below the horizon in 2004 . In the following nights the object was still in the northern sky, but was again much weaker due to the increased distance.
Due to the short distance there was a large parallax of about 5 degrees in Germany, depending on the respective geographical location, and thus deviations from the geocentric positions given in the ephemeris . 2004 FH moved across the sky with a maximum of 33 arc seconds per time second .
See also
Web links
- Discovery report (English)
- Press release of the JPL (English)
- Confirmation recordings
- Detailed information for professionals (English)
- Closest Approaches of asteroids to the Earth (English)
- Ephemeridenrechner (English)