2007 VK184

2007 VK₁₈₄ is a sub-kilometer asteroid, classified as a near-Earth object of the Apollo group, and estimated to be approximately 130 meters (430 ft) in diameter.^[4] It was listed on the Sentry Risk Table with a Torino Scale rating of 1 for a potential impactor in June 2048.^[4] It was removed from the Sentry Risk Table on 28 March 2014.^[5]

2007 VK₁₈₄

The 2014 close approach of 2007 VK184[1]
Discovery[2]
Discovered by	Catalina Sky Survey (703)
Discovery date	12 November 2007
Designations
Minor planet category	Apollo NEO[1]
Orbital characteristics[1]
Epoch 2022-Aug-09 (JD 2459800.5)[1]
Uncertainty parameter 1[1]
Observation arc	6.37 years
Aphelion	2.7098 AU
Perihelion	0.74286 AU
Semi-major axis	1.7263 AU
Eccentricity	0.56969
Orbital period (sidereal)	828.5 d (2.27 yr)
Average orbital speed	22.8 km/s[a]
Mean anomaly	201.99°
Inclination	1.2208°
Longitude of ascending node	253.57°
Argument of perihelion	73.649°
Earth MOID	0.00044 AU (66,000 km)
Venus MOID	0.055 AU (8,200,000 km)[3]
Mars MOID	0.033 AU (4,900,000 km)
Physical characteristics
Mean diameter	~130 meters (430 ft)[4]
Mass	3.3×109 kg (assumed)[4]
Absolute magnitude (H)	22.0[1]

2023

The asteroid will come to opposition on 24 April 2023 when it will have a solar elongation of 177 degrees and an apparent magnitude of 22.^[6] Then on 15 July 2023 the asteroid will harmlessly pass 0.2275 AU (34.03 million km) from Earth.^[1]

Description

2007 VK₁₈₄ was discovered on 12 November 2007 by the Catalina Sky Survey.^[2] It was recovered on 26 March 2014 by Mauna Kea,^[7][3] and removed from the Sentry Risk Table on 28 March 2014.^[5] By 4 January 2008, with an observation arc of 52 days, there was a 1 in 2700 chance of an impact with Earth on 3 June 2048.^[8] The Sentry Risk Table, using an observation arc of 60 days, showed the asteroid had a 1 in 1820 chance (0.055%) of impacting Earth on 3 June 2048.^[4] Since the March 2014 recovery, it is known that the asteroid will pass 0.013 AU (1,900,000 km; 1,200,000 mi) from Earth on 2 June 2048.^[1]

2014 passage

Before the 2014 close approach, the asteroid had a modest observation arc of 60 days,^[4] and the imprecise trajectory of this asteroid was complicated by close approaches to Earth, Venus and Mars.^[1] On 23 May 2014, the asteroid passed 0.17 AU (25,000,000 km; 16,000,000 mi) from Earth^[1] and reached an apparent magnitude of ~20.8.^[9] As expected the close approach allowed astronomers to recover the asteroid on 26 March 2014 and refine the odds of a future collision.^[3] As the asteroid gets closer to Earth, the positional uncertainty becomes larger.^[10] By recovering the asteroid well before closest approach you can avoid searching a larger region of the sky.^[10] Most asteroids rated 1 on the Torino Scale are later downgraded to 0 after more observations come in.

Risk assessments were calculated based on a diameter of 130 meters.^[4] It was estimated that, if it were ever to impact Earth, it would enter the atmosphere at a speed of 19.2 km/s and would have a kinetic energy equivalent to 150 megatons of TNT.^[4] Assuming the target surface is sedimentary rock, the asteroid would impact the ground with the equivalent of 40 megatons of TNT and create a 2.1 kilometers (1.3 mi) impact crater.^[11] Asteroids of approximately 130 meters in diameter are expected to impact Earth once every 11000 years or so.^[11]

2048

On 26–27 March 2014, additional observations were made which ruled out the chance of an impact in 2048.^[10] On 2 June 2048 the asteroid will pass 5 lunar distances from Earth^[1] with a 3-sigma uncertainty region of ±20000 km.^[12]

2118

By the Earth approach of June 2118 the known approaches become more divergent.

2118 Earth approach

Date	Minimum possible approach	Maximum possible approach
2118-Jun-06 ± 2 days	0.00089 AU (133 thousand km)[1][13]	0.041 AU (6.1 million km)[1]

See also

• 99942 Apophis, a NEO that, for a few days, was thought to have a slight probability of striking the Earth in 2029. But the likelihood that would happen was quickly determined to be zero.

Notes

1. v = 42.1219 √1/r − 0.5/a, where r is the distance from the Sun, and a is the major semi-axis. Average velocity is at r=a=1.7 AU.