2014 HQ₁₂₄ is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Aten group, approximately 400 meters (1,300 feet) in diameter. It passed 3.25 lunar distances (LD) from Earth on 8 June 2014.[8] It was discovered on 23 April 2014 by NEOWISE.[2] It is estimated that an impact event would have had the energy equivalent of 2,000 megatons of TNT and would have created a 5 km (3 mi) impact crater.[9] The news media misleadingly nicknamed it The Beast.[10] 2014 HQ₁₂₄ previously passed this close to Earth in 1952[8] and will not again until at least 2307.[11] Radar imaging suggests it may be a contact binary.[12]

2014 HQ₁₂₄

Radar image of 2014 HQ124 taken by the Arecibo Observatory on 8 June 2014
Discovery[1][2]
Discovered by	NEOWISE (C51)
Discovery date	23 April 2014
Designations
MPC designation	2014 HQ124
Minor planet category	NEO · Aten · PHA[1][3]
Orbital characteristics[3]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 1
Observation arc	4.09 yr (1,495 d)
Aphelion	1.0712 AU
Perihelion	0.6303 AU
Semi-major axis	0.8508 AU
Eccentricity	0.2591
Orbital period (sidereal)	287 days
Mean anomaly	97.870°
Mean motion	1° 15m 21.6s / day
Inclination	26.371°
Longitude of ascending node	257.56°
Argument of perihelion	144.51°
Earth MOID	0.0084 AU (3.27 LD)
Physical characteristics
Mean diameter	0.409±0.168 km[4][5]
Synodic rotation period	>16 h[6][7]
Geometric albedo	0.291±0.216[4][5]
Spectral type	S (assumed)[6]
Absolute magnitude (H)	18.9[1][3]

Orbit

2014 HQ₁₂₄ orbits the Sun at a distance of 0.6–1.1 AU once every 0 years and 9 months (287 days; semi-major axis of 0.85 AU). Its orbit has an eccentricity of 0.26 and an inclination of 26° with respect to the ecliptic.[3]

2014 close approach

On 6 June 2014, the asteroid brightened to about apparent magnitude 13.7 while in the southern constellation of Horologium.[13] Near its closest approach to Earth of 3.25 lunar distances on 8 June 2014, the asteroid crossed the celestial equator, making it a northern hemisphere object. It however had an elongation of about 20 degrees from the Sun,[13] and was lost in astronomical twilight during the closest approach to Earth. The Goldstone Deep Space Network observed the asteroid later on 8 June 2014,[14] when the asteroid was between 3.6 and 3.8 lunar distances.[12]

2014 HQ₁₂₄ orbit showing high inclination and 2014 Earth flyby

The sky trajectory of 2014 HQ₁₂₄, as seen from earth, with 12-hour motion markers

Physical characteristics

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, 2014 HQ₁₂₄ measures (0.409±0.168) kilometers in diameter and its surface has an albedo of (0.291±0.216) based on an absolute magnitude of 18.9.[4][5]

Radar observations at Goldstone suggest that the object is elongated and irregular in shape, with its long axis measuring at least 370 meters (1,200 feet). Lance Benner suspects it the be a contact binary, composed of two merged objects forming a single asteroid with a lobed shape.[12]

Photometric observations by astronomers with the Mission Accessible Near-Earth Objects Survey (MANOS) and subsequent evaluation by Brian Warner's Collaborative Asteroid Lightcurve Link, determined that 2014 HQ₁₂₄ has a rotation period of at least 16 hours.[6][7] While the object's spectral type is unknown, Warner assumes it to be an S-type asteroid, based on its high albedo, which is typical for stony asteroids.[6]

Related objects

On average, an object about the size of 2014 HQ₁₂₄ will pass this close to Earth every few years.[15] Similar events, where other 100+ meter diameter asteroids have or will soon pass less than 4 LD from Earth, include:

• 4179 Toutatis (~3000 meters in diameter) passed 4.0 LD from Earth on 29 September 2004
• 2004 XP14 (~500 meters in diameter) passed 1.1 LD from Earth on 3 July 2006
• (308635) 2005 YU55 (~360 meters in diameter) passed 0.8 LD from Earth on 8 November 2011
• 2014 EG₄₅ (~140 meters in diameter) passed 3.2 LD from Earth on 4 March 2014[16]
• (357439) 2004 BL86 (~600 meters in diameter) passed 3.1 LD from Earth on 26 January 2015[17]

See also

• List of asteroid close approaches to Earth in 2014

References

External links

• Near-Earth Asteroid 2014 HQ124 (Slooh broadcast 5 June 2014)
• High Resolution Radar at Arecibo Observatory Reveals Asteroid As a Beauty, Not a Beast (USRA June 12, 2014)
• 2014 HQ124 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• 2014 HQ124 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical Properties · Summary
• 2014 HQ124 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters