is a sub-kilometer asteroid, classified as

near-Earth object A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...

and

potentially hazardous asteroid A potentially hazardous object (PHO) is a near-Earth object – either an asteroid or a comet – with an orbit that can make close approaches to the Earth and is large enough to cause significant regional damage in the event of impact. They are ...

of the Aten group, approximately in diameter. It passed 3.25 lunar distances (LD) from Earth on 8 June 2014. It was discovered on 23 April 2014 by

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 201 ...

. It is estimated that an impact event would have had the energy equivalent of 2,000

megatons TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a m ...

of TNT and would have created a

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...

. The

news media The news media or news industry are forms of mass media that focus on delivering news to the general public or a target public. These include news agencies, print media (newspapers, news magazines), broadcast news (radio and television), and ...

misleadingly nicknamed it ''The Beast''. previously passed this close to Earth in 1952 and will not again until at least 2307.

Radar Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, we ...

imaging suggests it may be a

contact binary In astronomy, a contact binary is a binary star system whose component stars are so close that they touch each other or have merged to share their gaseous envelopes. A binary system whose stars share an envelope may also be called an overconta ...

Orbit

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 Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.26 and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

of 26 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic agains ...

2014 close approach

On 6 June 2014, the asteroid brightened to about

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

13.7 while in the southern constellation of Horologium. Near its closest approach to Earth of 3.25 lunar distances on 8 June 2014, the asteroid crossed the

celestial equator The celestial equator is the great circle of the imaginary celestial sphere on the same plane as the equator of Earth. This plane of reference bases the equatorial coordinate system. In other words, the celestial equator is an abstract proj ...

, making it a northern hemisphere object. It however had an elongation of about 20 degrees from the Sun, 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, when the asteroid was between 3.6 and 3.8 lunar distances.

Physical characteristics

According to the survey carried out by the

mission of NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 201 ...

, measures () kilometers in diameter and its surface has an

albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...

of () based on an

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it ...

of 18.9. Radar observations at Goldstone suggest that the object is elongated and irregular in shape, with its long axis measuring at least .

Lance Benner A lance is a spear designed to be used by a mounted warrior or cavalry soldier ( lancer). In ancient and medieval warfare, it evolved into the leading weapon in cavalry charges, and was unsuited for throwing or for repeated thrusting, unlike s ...

suspects it the be a

, composed of two merged objects forming a single asteroid with a lobed shape. Photometric observations by astronomers with the ''Mission Accessible Near-Earth Objects Survey'' (MANOS) and subsequent evaluation by Brian Warners ''Collaborative Asteroid Lightcurve Link'', determined that has a rotation period of at least 16 hours. While the object's

spectral type In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the ...

is unknown, Warner assumes it to be an

S-type asteroid S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the secon ...

, based on its high albedo, which is typical for stony asteroids.

Related objects

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

4179 Toutatis 4179 Toutatis, provisional designation , is an elongated, stony asteroid and slow rotator, classified as a near-Earth object and potentially hazardous asteroid of the Apollo asteroid and Alinda asteroid groups, approximately 2.5 kilometers in ...

(~3000 meters in diameter) passed 4.0 LD from Earth on 29 September 2004 * (~500 meters in diameter) passed 1.1 LD from Earth on 3 July 2006 * (~360 meters in diameter) passed 0.8 LD from Earth on 8 November 2011 * (~140 meters in diameter) passed 3.2 LD from Earth on 4 March 2014 * (~600 meters in diameter) passed 3.1 LD from Earth on 26 January 2015

References

External links