18 notable near-Earth asteroids, from 37 km Ganymed to 11 m 1998 KY26
A near-Earth object is an asteroid or comet whose orbit brings it within 1.3 AU of the Sun, which puts it within about 45 million km of Earth's orbit. One is potentially hazardous if it is larger than about 140 m and its orbit passes within 0.05 AU, 7.5 million km, of Earth's. More than 42,000 near-Earth asteroids are known; the table lists the best known, including every one visited by a spacecraft. Sort any column; the buttons filter by orbit group.
| Asteroid | Group | Diameter km | Average distance AU | Potentially hazardous | Spacecraft | Note |
|---|---|---|---|---|---|---|
| 1036 Ganymed | Amor | 37.67 | 2.665 | Largest near-Earth asteroid | ||
| 433 Eros | Amor | 16.84 | 1.4581 | NEAR Shoemaker orbit 2000-02-14 to 2001-02-12; landed 2001-02-12 | First near-Earth asteroid discovered; first asteroid orbited and landed on | |
| 3200 Phaethon | Apollo | 5.1 | 1.2715 | Yes | Parent of the Geminid meteor shower; target of JAXA DESTINY+ | |
| 3122 Florence | Amor | 4.35 | 1.7691 | Yes | Triple system; 2017-09-01 pass at 0.047 AU reached V 8.5; VMagMax 2017-09-01 | |
| 4179 Toutatis | Apollo | 2.5 | 2.5336 | Yes | Chang'e 2 flyby 2012-12-13 | Tumbling contact binary; imaged by China's Chang'e 2 |
| 1620 Geographos | Apollo | 2.5 | 1.2454 | Yes | Highly elongated; radar imaged 1994 | |
| 3753 Cruithne | Aten | 2.07 | 0.9978 | Earth co-orbital in a horseshoe-like orbit | ||
| 1566 Icarus | Apollo | 1.4 | 1.0781 | Yes | Perihelion inside Mercury orbit | |
| 162173 Ryugu | Apollo | 0.896 | 1.191 | Yes | Hayabusa2 2018-06-27 to 2019-11-13; sample returned 2020-12-05 | Rubble-pile spinning top; Hayabusa2 made an artificial crater |
| 65803 Didymos | Apollo | 0.761 | 1.6443 | Yes | DART impact on Dimorphos 2022-09-26; LICIACube flyby 2022-09-26; Hera (arrival planned Nov 2026) | DART kinetic impact shortened Dimorphos orbit by about 33 min (to 11.37 h) |
| 98943 Torifune | Apollo | 0.54 | 1.0322 | Hayabusa2 flyby 2026-07-05 | Hayabusa2 passed about 400 m from the surface; about 840 x 340 m | |
| 101955 Bennu | Apollo | 0.49 | 1.126 | Yes | OSIRIS-REx 2018-12-03 to 2021-05-10; sample returned 2023-09-24 | Rubble pile; 1-in-2700 impact chance in 2182 |
| 99942 Apophis | Aten | 0.34 | 0.9224 | Yes | OSIRIS-APEX (arrival planned 2029) | Passes about 32,000 km from Earth on 2029-04-13; naked-eye object then; VMagMax predicted for 2029-04-13 |
| 25143 Itokawa | Apollo | 0.33 | 1.3241 | Yes | Hayabusa 2005 (touchdown); sample returned 2010-06-13 | First asteroid sample returned to Earth |
| 2010 TK7 | Aten | 0.3 | 0.9988 | First Earth trojan discovered (L4) | ||
| 2024 YR4 | Apollo | 0.06 | 2.5158 | Peak Earth-impact chance 3.1% (2025-02-18) for 2032-12-22, later ruled out; JWST (Feb 2026) ruled out a lunar impact too | ||
| 469219 Kamo'oalewa | Apollo | 0.05 | 1.0012 | Tianwen-2 (arrived 2026-07-04; sampling planned; Earth return planned 2027-11-29) | Earth quasi-satellite; possibly lunar ejecta; China's Tianwen-2 sample-return target | |
| 1998 KY26 | Apollo | 0.011 | 1.2318 | Hayabusa2 (arrival planned 2031) | Fast rotator about 11 m across; Hayabusa2 extended-mission target |
Almost all near-Earth asteroids 1 km and larger have been found, but fewer than half of those 140 m and larger
Counts from NASA's Planetary Defense Coordination Office; the 30 to 100 m estimate is ESA's. Discoveries are accelerating: the 40,000th near-Earth asteroid was found in November 2025, and a quarter of all known were found in the three years before. The first, Eros, was found in 1898; by 1980 only 44 were known. Small asteroids are the gap. One like the 20 m Chelyabinsk impactor of February 15, 2013, whose airburst injured about 1,500 people, is usually found only days before impact, if at all. About a dozen asteroids have been spotted before hitting the atmosphere, the first being 2008 TC3 over Sudan in 2008.
Impact risks are rated on the Torino scale, and almost every alert drops to zero as the orbit is refined
NASA's Sentry system and ESA's Aegis compute impact chances for every newly found object for the next century. The Torino scale rates them from 0, no hazard, to 10, a certain global catastrophe. A new asteroid's orbit is uncertain, and the range of possible paths often includes Earth at first; as observations come in, the range shrinks and the chance usually falls to zero. No known asteroid larger than 140 m has a significant chance of hitting Earth in the next 100 years.
2024 YR4 reached a 3.1% chance of hitting Earth in 2032 before it was ruled out
Found in December 2024, the 60 m asteroid 2024 YR4 reached Torino scale 3 and a 3.1% chance of hitting Earth on December 22, 2032, on February 18, 2025, the highest ever recorded for an object that size. More observations ruled out an Earth impact within weeks. A small chance that it would hit the Moon remained until observations with the Webb telescope in early 2026 ruled that out too.
Apophis will pass 32,000 km from Earth on April 13, 2029, closer than geostationary satellites and bright enough to see without a telescope
The 340 m asteroid Apophis briefly had a 2.7% chance of hitting Earth in 2029 after its discovery in 2004; it will miss, and no impact is possible for at least the next 100 years. On April 13, 2029, it will shine at about magnitude 3 over Europe, Africa and western Asia. ESA's Ramses, built with Japan's JAXA under an agreement signed in May 2026, is due to launch in April 2028 and arrive in February 2029 to watch Earth's gravity shake the asteroid. NASA's OSIRIS-APEX, the spacecraft that brought back samples from Bennu, arrives in June 2029 for an 18-month study.
NASA's DART proved in 2022 that a spacecraft can push an asteroid, and China plans its own test
- DART (NASA) hit Dimorphos, the 160 m moon of Didymos, on September 26, 2022, at 6 km/s and shortened its 12-hour orbit by about 33 minutes, far more than the impact alone could, because of the debris it blasted off.
- Hera (ESA), launched in October 2024, reaches Didymos in late 2026 to measure the crater and the mass of Dimorphos, turning DART's result into a usable recipe.
- China's kinetic impactor test (CNSA) would send an observer and an impactor on one rocket around 2027 to the 30 m asteroid 2015 XF261; the observer watches the impact and studies the result for 6 to 12 months. In June 2026 CNSA also announced a coordinated ground and space network to monitor near-Earth asteroids.
- Other methods under study include gravity tractors, ion-beam shepherds and, for a large asteroid found late, a nuclear explosion beside it. All need years of warning, which is why finding asteroids early matters most.
NEO Surveyor, launching in 2027, is the first space telescope built to hunt hazardous asteroids
Most discoveries come from the Catalina Sky Survey and Pan-STARRS in the US, the ATLAS network in Hawaii, Chile and South Africa, and the Zwicky Transient Facility. The Vera C. Rubin Observatory, which found more than 30 new near-Earth objects in its first weeks of testing in 2025, should multiply the discovery rate. NASA's NEO Surveyor, a 50 cm infrared telescope due to launch on a Falcon 9 no earlier than September 2027, will watch from the Sun-Earth L1 point, where it can see asteroids coming from the direction of the Sun, as Chelyabinsk did, and aims to find two-thirds of the remaining 140 m objects within five years. Asteroids · Earth's quasi-moons · Impact craters