2007 TU24 is an Apollo near-Earth asteroid that was discovered by the Catalina Sky Survey in Arizona on 11 October 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 29 January 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 2007 TU24 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]
 Radar image of 2007 TU24 | |||||||||
| Discovery | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Discovered by | Catalina Sky Survey | ||||||||
| Discovery date | 11 October 2007 | ||||||||
| Designations | |||||||||
| Orbital characteristics[2] | |||||||||
| Epoch 13 January 2016 (JD 2457400.5) | |||||||||
| Uncertainty parameter 0 | |||||||||
| Observation arc | 1093 days (2.99 yr) | ||||||||
| Aphelion | 3.1343 AU (468.88 Gm) | ||||||||
| Perihelion | 0.95153 AU (142.347 Gm) | ||||||||
| 2.0429 AU (305.61 Gm) | |||||||||
| Eccentricity | 0.53423 | ||||||||
| 2.92 yr (1066.5 d) | |||||||||
| 267.95° | |||||||||
| 0° 20m 15.144s / day | |||||||||
| Inclination | 5.6232° | ||||||||
| 127.041° | |||||||||
| 334.254° | |||||||||
| Earth MOID | 0.000483062 AU (72,265.0 km) | ||||||||
| Jupiter MOID | 2.06887 AU (309.499 Gm) | ||||||||
| Physical characteristics | |||||||||
| Dimensions | ~250 meters[3] | ||||||||
| Mass | < 2.4×1010 kg[4] | ||||||||
Mean density | unknown | ||||||||
Equatorial surface gravity | unknown | ||||||||
Equatorial escape velocity | < 0.58 km/h[4] | ||||||||
| 26 h (1.1 d)[2] | |||||||||
| 0.24 | |||||||||
| |||||||||
Impact risk assessment
editFrom 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
Goldstone Observatory carried out radar observations on January 23 and 24 January 2008. As of then, 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 29 January 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 1–4 February.[3] It is a contact binary asteroid.[9]
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 3 July 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 29 September 2004.
- On 7 August 2027, (137108) 1999 AN10 will pass within 388,960 km (0.0026 AU) of Earth
- On 13 April 2029, Apophis will pass the earth within the orbits of the geosynchronous communication satellites.
See also
editReferences
edit- ^ a b c d JPL Small-Body Database Browser: 2007TU24
- ^ a b c d "JPL Close-Approach Data: (2007 TU24)" (2010-10-08 last obs (arc=2.99 years)). Retrieved 30 March 2016.
- ^ 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.[dead link]
- ^ a b radius of 0.125 km; volume of a sphere * maximum likely density of 3 g/cm3 (though it could be a loose rubble pile) yields an improbable mass of 2.45×1010 kg and an improbable escape velocity of 0.58 km/h.
- ^ "Asteroid Zooms by Earth". NASA/JPL. 29 January 2008. Archived from the original on 2 February 2008. Retrieved 30 January 2008.
- ^ 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
- ^ NEOs Removed from Impact Risks Tables
- ^ 2007 TU24planning.html Archived 2008-01-20 at the Wayback Machine
- ^ Lance A. M. Benner (18 November 2013). "Binary and Ternary near-Earth Asteroids detected by radar". NASA/JPL Asteroid Radar Research. Archived from the original on 8 June 2004. Retrieved 1 March 2014.
External links
edit- Asteroid to Make Rare Close Flyby of Earth Archived 16 March 2012 at the Wayback Machine (Catalina Sky Survey Photo)
- Huge asteroid to fly by past earth.Independent Online
- Asteroid 2007 TU24: No Danger to Earth Archived 31 October 2011 at the Wayback Machine (Phil Plait 25 January 2008)
- 2007 TU24 at NeoDyS-2, Near Earth Objects—Dynamic Site
- 2007 TU24 at ESA–space situational awareness
- 2007 TU24 at the JPL Small-Body Database
