2012 KT42

2012 KT₄₂

Designations
Minor planet category	Apollo NEO
Orbital characteristics [1]
Epoch 13 January 2016 (JD  2457400.5)
Uncertainty parameter 5
Aphelion	2.4839  AU (371.59  Gm)
Perihelion	0.71144 AU (106.430 Gm)
Periastron	94.628°
Semi-major axis	1.5977 AU (239.01 Gm)
Eccentricity	0.55470
Orbital period (sidereal)	2.02  yr (737.60  d)
Mean anomaly	261.31°
Mean motion	0° 29m 17.052s / day
Inclination	2.1932°
Longitude of ascending node	69.515°
Argument of perihelion	259.13°
Earth  MOID	0.000968708 AU (144,916.7 km)
Physical characteristics
Dimensions	~4–10  metres [2]
Synodic rotation period	0.06057  h (3.634  min)
Absolute magnitude (H)	29 [3] 29.0 [1]

2012 KT₄₂ is an Apollo near-Earth asteroid first observed by astronomer Alex R. Gibbs of the Mount Lemmon Survey with a 1.5-meter reflecting telescope on 28 May 2012.

Overview

The asteroid had a close approach to the Earth on 29 May 2012, approaching to only ~8950 miles (~14,440 km) above the planet's surface. This means 2012 KT₄₂ came inside the Clarke Belt of geosynchronous satellites. In May 2012, the estimated 5- to 10-metre-wide asteroid ranked #6 on the top 20 list of closest-approaches to Earth. There was no danger of a collision during the close approach. 2012 KT₄₂ passed roughly 0.01  AU (1,500,000  km ; 930,000  mi ) from Venus on 8 July 2012. ^[1]

It is estimated that an impact would produce an upper atmosphere air burst equivalent to 11 kt TNT, ^[4] roughly equal to Hiroshima's Little Boy. The asteroid would be vaporized as these small impacts occur approximately once per year. A comparable-sized object caused the Sutter's Mill meteorite in California on 2 April 2012. It was removed from the Sentry Risk Table on 30 May 2012. ^[5]

References

1. "JPL Close-Approach Data: (2012 KT42)" (last observation: 2012-05-29; arc: 1 day; uncertainty: 5). Retrieved 1 April 2016.
2. "Conversion of Absolute Magnitude to Diameter". Minor Planet Center . Retrieved 30 May 2012.
3. "2012 KT42 Orbit". Minor Planet Center. 29 May 2012. Retrieved 30 May 2012.
4. "Earth Impact Risk Summary: 2012 KT42". NASA/JPL Near-Earth Object Program Office. Retrieved 29 May 2012.^{[ dead link ]}
5. "Date/Time Removed". NASA/JPL Near-Earth Object Program Office. Archived from the original on 2 June 2002. Retrieved 30 May 2012.

External links

• JPL Small-Body Database Browser for 2012 KT42
• 2012 KT42 - Close Approach (Remanzacco Observatory in Italy)
• Images from Flyby (spaceweather.com)
• MPEC 2012-K66 : 2012 KT42 (Minor Planet Center Discovery announcement)
• Planetary Defense Blog post on 2012 KT42
• Video: Tiny Asteroid 2012 KT42 Crossing The Sky (universetoday 29 May 2012)
• The Peculiar Flyby of Asteroid 2012 KT42 (Pasquale Tricarico : 29 May 2012)
• 2012 KT42 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemerides  · Observation prediction  · Orbital info  · MOID  · Proper elements  · Observational info  · Close approaches  · Physical info  · Orbit animation
• 2012 KT42 at ESA–space situational awareness
  • Ephemerides  · Observations  · Orbit  · Physical properties  · Summary
• 2012 KT42 at the JPL Small-Body Database
  • Close approach  · Discovery  · Ephemeris  · Orbit viewer  · Orbit parameters  · Physical parameters