Near-Earth object

Small Solar System body with an orbit that can bring it close to Earth

A near-Earth object (NEO) is by definition 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 around the Sun, rather than its current position, thus an object with such an orbit is considered a NEO even at times when it is far from making a close approach of Earth. If a NEO's orbit crosses the Earth's orbit, and the object is larger than 140 meters (460 ft) across, it is, by definition, considered a potentially hazardous object (PHO).

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