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2007 TU24 is an Apollo near-Earth 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.[3] 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.[3]

2007 TU24
2007 TU24 radar image 20080128.jpg
Radar image of 2007 TU24.
Courtesy NASA/JPL-Caltech
Discovered byCatalina Sky Survey
Discovery dateOctober 11, 2007
Apollo, NEO, PHA[1]
Orbital characteristics[2]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0
Observation arc1093 days (2.99 yr)
Aphelion3.1343 AU (468.88 Gm)
Perihelion0.95153 AU (142.347 Gm)
2.0429 AU (305.61 Gm)
2.92 yr (1066.5 d)
0° 20m 15.144s /day
Earth MOID0.000483062 AU (72,265.0 km)
Jupiter MOID2.06887 AU (309.499 Gm)
Physical characteristics
Dimensions~250 meters[3]
Mass< 2.4×1010 kg[4]
Mean density
Equatorial surface gravity
Equatorial escape velocity
< 0.58 km/h[4]
26 h (1.1 d)[2]
Surface temp. min mean max
Kelvin unknown
20.2,[1] 20.3[2]


Impact risk assessmentEdit

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 passageEdit

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.[8] 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.[2]

Observations from Arecibo Observatory were taken on February 1–4.[3] It is a contact binary asteroid.[9]

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

Other close approachesEdit

See alsoEdit


  1. ^ a b c d JPL Small-Body Database Browser: 2007TU24
  2. ^ a b c d "JPL Close-Approach Data: (2007 TU24)" (2010-10-08 last obs (arc=2.99 years)). Retrieved 30 March 2016.
  3. ^ a b c d "NASA Scientists Get First Images of Earth Flyby Asteroid". NASA/JPL. 25 January 2008. Archived from the original on 29 January 2008. Retrieved 26 January 2008.
  4. ^ 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.
  5. ^ "Asteroid Zooms by Earth". NASA/JPL. 29 January 2008. Retrieved 30 January 2008.
  6. ^ Near-Earth Asteroid 2007 TU24 to Pass Close to Earth on Jan. 29 - Should be Observable with Modest Sized Telescopes Archived 2008-01-24 at the Wayback Machine
  7. ^ NEOs Removed from Impact Risks Tables
  8. ^ 2007 TU24planning.html Archived 2008-01-20 at the Wayback Machine
  9. ^ Dr. Lance A. M. Benner (18 November 2013). "Binary and Ternary near-Earth Asteroids detected by radar". NASA/JPL Asteroid Radar Research. Retrieved 1 March 2014.

External linksEdit