2007 TU24

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2007 TU24
2007 TU24 radar image 20080128.jpg
Radar image of 2007 TU24.
Courtesy NASA/JPL-Caltech
Discovery and designation
Discovered by Catalina Sky Survey
Discovery date October 11, 2007
Designations
Minor planet category Apollo,[1]
Earth-crosser asteroid
Orbital characteristics
Epoch February 4, 2008
Aphelion 3.140 AU
Perihelion 0.948 AU
2.044 AU
Eccentricity 0.536
2.92 a
9.045°
Inclination 5.628°
127.095°
334.165°
Physical characteristics
Dimensions ~250 meters[2]
Mass <2.4×1010 kg[3]
Mean density
unknown
Equatorial escape velocity
<0.58 km/h[3]
roughly once per day[4]
0.24
Surface temp. min mean max
Kelvin unknown
20.2[1]

2007 TU24 is an asteroid that was discovered by the Catalina Sky Survey in Arizona on October 11, 2007. Imaging radar has estimated that it is 250 meters (820 ft) in diameter.[2] The asteroid passed 554,209 kilometer (344,370 mile or 1.4-lunar distance)[5] from Earth on January 29, 2008, at 08:33 UTC. (At the time of the passage it was believed the closest for any known potentially hazardous asteroid (PHA) of this size before 2027,[6] but in 2010 2005 YU55 was measured to be 400 meters in diameter.) At closest approach the asteroid had an apparent magnitude of 10.3 and was about 50 times fainter than the naked eye can see. It required about a 3-inch (76 mm) telescope to be seen.[2]

Impact risk assessment[edit]

From the date of discovery of asteroid 2007 TU24 on 11 October 2007, a total of 316 observations of it had been made by 31 January 2008, spanning 112 days.[1] Now the asteroid has an observation arc of about 3 years and the trajectory is well defined.[1] It was removed from the Sentry Risk Table on 4 December 2007 at 14:05 UTC.[7]

2008 passage[edit]

A series of low-resolution radar images of asteroid 2007 TU24

Goldstone Observatory carried out radar observations on January 23 and January 24, 2008. As of January 24, the orbit of the asteroid was known with such a high precision that scientists were able to calculate close approaches from the year 67 AD to 2141 AD.[4] On January 29, 2008 at 08:33 UTC, 2007 TU24 passed by the earth at a nominal distance of 0.0037043 AU (554,160 km; 344,340 mi) with a relative speed of 9.248 km/s.[8]

Observations from Arecibo Observatory were taken on February 1–4.[2] It is a contact binary asteroid.[9]

Animation of two photos taken from Slooh Teide observatory on Jan 31, 2008

Other close approaches[edit]

  • Asteroid 2004 XP14 was the closest potentially hazardous asteroid, passing Earth by 432,308 km (268,624 mi), 0.00289 AU, or just 1.1 times the Moon's average distance from Earth on July 3, 2006.
  • Asteroid 4179 Toutatis (4.5 km diameter) came within 1.5 million km, 0.0104 AU (within 4 lunar distances) of the Earth on September 29, 2004.

See also[edit]

References[edit]

  1. ^ a b c d JPL Small-Body Database Browser: 2007TU24
  2. ^ a b c d "NASA Scientists Get First Images of Earth Flyby Asteroid". NASA/JPL. 2008-01-25. Archived from the original on 29 January 2008. Retrieved 2008-01-26. 
  3. ^ a b radius of 0.125 km; volume of a sphere * maximum likely density of 3g/cm³ (though it could be a loose rubble pile) yields an improbable mass of 2.45e10 kg and an improbable escape velocity of 0.58 km/h.
  4. ^ a b 2007 TU24planning.html
  5. ^ "Asteroid Zooms by Earth". NASA/JPL. 2008-01-29. Retrieved 2008-01-30. 
  6. ^ Near-Earth Asteroid 2007 TU24 to Pass Close to Earth on Jan. 29 - Should be Observable with Modest Sized Telescopes
  7. ^ NEOs Removed from Impact Risks Tables
  8. ^ "JPL Close-Approach Data: (2007 TU24)". 2010-10-08 last obs (arc=2.99 years). Retrieved 2011-11-09. 
  9. ^ Dr. Lance A. M. Benner (2013-11-18). "Binary and Ternary near-Earth Asteroids detected by radar". NASA/JPL Asteroid Radar Research. Retrieved 2014-03-01. 

External links[edit]