is a very bright micro-

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

, classified as a

near-Earth object A near-Earth object (NEO) is any small Solar System body orbiting the Sun whose closest approach to the Sun ( perihelion) is less than 1.3 times the Earth–Sun distance (astronomical unit, AU). This definition applies to the object's orbit a ...

of the

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, less than in diameter. It was first observed by astronomers of the

Catalina Sky Survey Catalina Sky Survey (CSS; obs. code: 703) is an astronomical survey to discover comets and asteroids. It is conducted at the Steward Observatory's Catalina Station, located near Tucson, Arizona, in the United States. CSS focuses on the searc ...

Mount Lemmon Observatory Mount Lemmon Observatory (MLO), also known as the Mount Lemmon Infrared Observatory, is an astronomy, astronomical observatory located on Mount Lemmon in the Santa Catalina Mountains approximately northeast of Tucson, Arizona, Tucson, Arizona (U ...

, Arizona, on 4 February 2018, during its sub-lunar close encounter with Earth.

2018 flyby

On 9 February 2018, the asteroid passed about from Earth, traveling relative to Earth and briefly reaching

apparent magnitude Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), ...

13. It was observed by the

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, which constrained its size to no more than 20 meters. During the flyby its period was changed from 1.48 years to 1.67 years.

Flyby gallery

File:2018CB skypath.png, Its path across the sky on February 9 was north to south (30 minute positions shown) File:2018CB earthflyby.png, Seen from space, it passes just outside geosynchronous orbit File:2018 CB Northolt Branch Observatory Feb7 video.gif, 20 minute timelapse, taken two days before closest approach. The asteroid can be seen near the center of the image, moving towards the lower left. Brightness is inverted (stars appear dark, the sky background appears light). File:2018 CB Northolt Branch Observatory Feb7 stack.png, 2018 CB on February 7. The image is corrected for the asteroid's motion, so stars appear trailed.

Other flybys

's orbit is in Earth's neighborhood, so it frequently makes other close approaches to Earth like the 2018 one, although not usually as close. In 1953 (65 years or 44 orbits earlier), it passed from Earth, and in 2090 it will pass between and from Earth. It also may have passed similarly near Earth in 1914, but the uncertainty in the 1953 approach makes it difficult to determine.

Physical characteristics

appears unusually bright for its size, suggesting it is made of brighter materials than the average asteroid.

References

External links

Minor Planet Circular The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Function ...