(410777) 2009 FD

(410777) 2009 FD

(410777) 2009 FD
VLT image of the very faint near-Earth asteroid 2009 FD
Discovery[1][2][3]
Discovered by Spacewatch (691)
Discovery date 24 February 2009
Designations
MPC designation (410777) 2009 FD
Apollo NEO[4]
Orbital characteristics[4]
Epoch 2013-Nov-04
(Uncertainty=0)[4]
Aphelion 1.7361 AU (Q)
Perihelion 0.58960 AU (q)
1.1628 AU (a)
Eccentricity 0.49296
1.25 yr
196.02° (M)
Inclination 3.1361°
9.4968°
281.30°
Physical characteristics
Dimensions ~472 meters (1,549 ft)[4][5][6]
Mass 8.3×1010 kg (assumed)[6]
4.0 h[4]
Albedo 0.01 (dark)[4]
Spectral type
C[7]
22.1[4]

(410777) 2009 FD (also written as 2009 FD) is an Apollo asteroid[4] (a class of near-Earth asteroid) with an orbit that places it at risk of a possible future collision with Earth in 2185. It has the highest impact threat of all known asteroids on the Palermo Technical Impact Hazard Scale based on its estimated diameter of 470 meters, kinetic yield, impact probability, and time interval.[8]

(410777) 2009 FD was initially announced as discovered on 16 March 2009 by La Sagra Sky Survey.[1] Because there were previous observations found in images taken by the Spacewatch survey some 3 weeks prior, on 24 February 2009, the Minor Planet Center assigned the discovery credit to Spacewatch under the discovery assignment rules.[2][3] (410777) 2009 FD made a close pass to Earth on 27 March 2009 at a distance of 0.004172 AU (624,100 km; 387,800 mi)[9][10] and another on 24 October 2010 at 0.0702 AU.[9] (410777) 2009 FD was recovered at apparent magnitude 23[note 1] on 30 November 2013 by Cerro Paranal Observatory,[3] several months before the close approach of April 2014 when it passed 0.1 AU from Earth.[9] It brightened to roughly apparent magnitude 19.3 around mid-March 2014.[11] One radar Doppler observation of (410777) 2009 FD was made in 2014.[4] The October–November 2015 Earth approach will be studied by the Goldstone Deep Space Network.[12]

NASA's Near Earth Program originally estimated its size to be 130 metres in diameter based on an assumed albedo of 0.15.[13] This gave it an estimated mass of around 2,800,000 tonnes.[13] But work by Amy Mainzer using NEOWISE data shows that it could be as large as 472 metres with an albedo as low as 0.01.[4][5] Because (410777) 2009 FD (K09F00D) was only detected in two (W1+W2) of the four wavelengths the suspected NEOWISE diameter is more of an upper limit.[5]

The JPL Small-Body Database shows that (410777) 2009 FD will make two very close approaches in the late 22nd century, with the approach of 29 March 2185 currently having a 1 in 385 chance of impacting Earth.[6] The nominal 2185 Earth approach distance is 0.009 AU (1,300,000 km; 840,000 mi).[9] Orbit determination for 2190 is complicated by the 2185 close approach.[9] The precise distance that it will pass from Earth and the Moon on 29 March 2185 will determine the 30 March 2190 distance. (410777) 2009 FD should pass closer to the Moon than Earth on 29 March 2185.[9] An impact by (410777) 2009 FD would cause severe devastation to a large region or tsunamis of significant size.[14] Due to (410777) 2009 FD's size, and its interactions with Mars and Venus, which increase its orbital uncertainty over time, it is rated −0.40 on the Palermo Scale, placing it higher on the Sentry Risk Table than any other known object.[8]

Past Earth-impact estimates

In January 2011, near-Earth asteroid (410777) 2009 FD (with observations through 7 December 2010) was listed on the JPL Sentry Risk Table with a 1 in 435 chance of impacting Earth on 29 March 2185.[13] In 2014 (with observations through 5 February 2014 creating an observation arc of 1807 days) the potential 2185 impact was ruled out.[15] Using the 2014 observations, the Yarkovsky effect has become more significant than the position uncertainties.[7][16][17] The Yarkovsky effect has resulted in the 2185 virtual impactor returning.

See also

Notes

  1. ^ At an apparent magnitude of 23, (410777) 2009 FD was roughly 4 million times fainter than can be seen with the naked eye.
    Math: (\sqrt[5]{100})^{23-6.5}\approx 3981071

References

  1. ^ a b (K09F00D)
  2. ^ a b
  3. ^ a b c
  4. ^ a b c d e f g h i j
  5. ^ a b c (listed as K09F00D)
  6. ^ a b c
  7. ^ a b
  8. ^ a b Sentry Risk Table
  9. ^ a b c d e f
  10. ^ Near Earth Asteroid 2009 FD - whilst you were sleeping! (ice in space)
  11. ^
  12. ^
  13. ^ a b c (2.3e-03 = 1 in 435 chance)
  14. ^ How a Near-Earth Object Impact Might Affect Society, 9 January 2003, Clark R. Chapman, SwRI, Boulder CO USA
  15. ^
  16. ^
  17. ^ (2.64e-3 = 1 in 379 chance)

External links

  • ESA/ESO Collaboration Successfully Tracks Its First Potentially Threatening Near-Earth Object (ESO 21 January 2014)