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). If a NEO's orbit crosses the Earth's, and the object is larger than 140 meters (460 ft) across, it is considered a potentially hazardous object (PHO). Most known PHOs and NEOs are asteroids, but a small fraction are comets.
The Aten asteroids are a dynamical group of asteroids whose orbits bring them into proximity with Earth. By definition, Atens are Earth-crossing asteroids (a < 1.0 AU and Q > 0.983 AU). The group is named after 2062 Aten, the first of its kind, discovered on 7 January 1976 by American astronomer Eleanor Helin at Palomar Observatory. As of 2020, 1841 Atens have been discovered, of which 13 are named. Many Atens are classified as potentially hazardous asteroids.
The Amor asteroids are a group of near-Earth asteroids named after the archetype object 1221 Amor. The orbital perihelion of these objects is close to, but greater than, the orbital aphelion of Earth, with most Amors crossing the orbit of Mars. The Amor asteroid 433 Eros was the first asteroid to be orbited and landed upon by a robotic space probe.
Eleanor Francis "Glo" Helin was an American astronomer. She was principal investigator of the Near-Earth Asteroid Tracking (NEAT) program of NASA's Jet Propulsion Laboratory.
2062 Aten, provisional designation 1976 AA, is a stony sub-kilometer asteroid and namesake of the Aten asteroids, a subgroup of near-Earth objects. The asteroid was named after Aten from Egyptian mythology.
2010 RF12 is a very small asteroid, classified as near-Earth object of the Apollo group, that passed between Earth and the Moon on 8 September 2010, at 21:12 UTC, approaching Earth within 79,000 kilometres (49,000 mi) above Antarctica. It is listed on the Sentry Risk Table as the asteroid with the greatest known probability (5%) of impacting Earth. On 5 September 2096 the asteroid will approach the Earth and the line of variation (LOV) passes through where the Earth will be. The asteroid was discovered by the Mount Lemmon Survey near Tucson, Arizona on 5 September 2010 along with 2010 RX30.
2011 CQ1 is a meteoroid discovered on 4 February 2011 by Richard A. Kowalski, at the Catalina Sky Survey. On the same day the meteoroid passed within 0.85 Earth radii (5,480 kilometers (3,410 mi)) of Earth's surface, and was perturbed from the Apollo class to the Aten class of near-Earth objects. With a relative velocity of only 9.7 km/s, had the asteroid passed less than 0.5 Earth radii from Earth's surface, it would have fallen as a brilliant fireball. The meteoroid is between 80 centimeters (31 in) and 2.6 meters (100 in) wide. The meteoroid was removed from the Sentry Risk Table on 5 February 2011.
367943 Duende, provisional designation 2012 DA14, is a micro-asteroid and a near-Earth object of the Aten and Atira group, approximately 30 meters (98 ft) in diameter. It was discovered by astronomers of the Astronomical Observatory of Mallorca at its robotic La Sagra Observatory in 2012, and named for the duende, a goblin-like creature from Iberian and Filipino mythology and folklore. Duende is likely an uncommon L-type asteroid and significantly elongated. For an asteroid of its size, it has a relatively long rotation period of 9.485 hours.
The Chelyabinsk meteor was a superbolide that entered Earth's atmosphere over the southern Ural region in Russia on 15 February 2013 at about 09:20 YEKT. It was caused by an approximately 20 m (66 ft) near-Earth asteroid that entered the atmosphere at a shallow 18.3 ± 0.4 degree angle with a speed relative to Earth of 19.16 ± 0.15 kilometres per second. The light from the meteor was briefly brighter than the Sun, visible up to 100 km (62 mi) away. It was observed over a wide area of the region and in neighbouring republics. Some eyewitnesses also felt intense heat from the fireball.
The Chelyabinsk meteorite is the fragmented remains of the large Chelyabinsk meteor of 15 February 2013 which reached the ground after the meteor's passage through the atmosphere. The descent of the meteor, visible as a brilliant superbolide in the morning sky, caused a series of shock waves that shattered windows, damaged approximately 7,200 buildings and left 1,500 people injured. The resulting fragments were scattered over a wide area.
2006 JY26 is a near-Earth object that is also horseshoe companion to the Earth like 3753 Cruithne.
2011 EO40 is an asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It is a possible candidate for the parent body of the Chelyabinsk superbolide.
2014 RC is a sub-kilometer near-Earth object and Apollo asteroid. The exceptionally fast rotator passed within 0.000267 AU (39,900 km; 24,800 mi) (0.1 lunar distances) of Earth on 7 September 2014. The asteroid is approximately the diameter of the Chelyabinsk meteor, and passed almost as close to Earth as 367943 Duende (2012 DA14) did in 2013.
2015 SO2 (also written 2015 SO2) is an Aten asteroid that is a temporary horseshoe companion to the Earth, the ninth known Earth horseshoe librator. Prior to its most recent close encounter with our planet (2015 September 30) it was an Apollo asteroid.
2017 DR109, is a micro-asteroid, classified as near-Earth object of the Apollo group and Aten group, respectively. It is currently trapped in a 1:1 mean motion resonance with the Earth of the horseshoe type. The object was first observed on 27 February 2017, by astronomers of the Catalina Sky Survey conducted at Mount Lemmon Observatory, Arizona, United States.
2017 VL2 is a micro-asteroid, classified as a near-Earth object of the Apollo group. It was first observed by ATLAS at Mauna Loa Observatory on 10 November 2017, a day after it passed inside the orbit of Earth.
2017 OO1 is a small asteroid, classified as near-Earth object of the Aten group, approximately 35–76 meters (115–249 feet) in diameter. It was first observed on 23 July 2017, by the robotic ATLAS survey at Mauna Loa Observatory, Hawaii, two days after the object had approached Earth at 0.33 lunar distances on 21 July 2017.
2018 VP1 is an Apollo near-Earth asteroid roughly 2 meters (7 feet) in diameter. The asteroid had a 0.41% chance (1 in 240) of impacting Earth on 2 November 2020 01:12 UT. It was discovered on 3 November 2018 when it was about 0.003 AU (450,000 km; 280,000 mi) from Earth and had a solar elongation of 165 degrees. The asteroid has a short 12.9 day observation arc. It was last observed on 16 November 2018 by the European Southern Observatory Very Large Telescope at apparent magnitude 26 pushing the telescope close to the limiting magnitude.
