Most Dangerous Asteroids in History


4) Apophis (99942 Apophis)

  • Area: 0.34 km² (340 m²)
  • Mass: 27 million tons (24 million metric tons)

Apophis, cataloged as (99942 Apophis), is one of the most watched near-Earth asteroids since it was discovered in June 2004 and has been classified as a threat since then. It has a diameter of about 340 meters (1,115 feet) and an estimated mass of about 27 million tons (24 million metric tons).

It was initially considered one of the most dangerous asteroids due to its predicted close approach to Earth. However, further observations have significantly reduced these concerns. Currently, Apophis poses no risk for at least the next century; its closest approach to Earth is on April 13, 2029.

Apophis will make a close approach to Earth in 2029, about 31,000 kilometers from Earth — closer than many satellites — allowing astronomers to study it up close.

This asteroid is an important case study in planetary defense strategy and demonstrates the need for continued monitoring of near-Earth objects.

5) 2023 DW

  • Size: Estimated to be around 50,000 tons
  • Mass: Equivalent to approximately 110 million pounds

2023 DW is a recently discovered near-Earth asteroid that has raised concerns about its potential risk of impact with Earth.

In early February 2023, astronomers discovered this asteroid using ground-based telescopes. It has a diameter of about 50 meters, but because it gradually approaches the Earth’s orbit over time, it is classified as a potentially hazardous asteroid.

Initial calculations indicate that the probability of a collision on February 14, 2046 is small – about one in six hundred; however, ongoing observations have significantly reduced this risk as more data on its trajectory and orbital dynamics become available.

While 2023 DW does not currently pose an immediate threat, monitoring such asteroids is still critical to planetary defense efforts to prevent possible future impacts.

6) 1979 XB

  • Area: 0.66 km² (660 m²)
  • Mass: estimated to be several hundred thousand tons

1979 XB is a near-Earth asteroid that was first observed on December 11, 1979. Due to its size and orbit intersecting with Earth’s orbit, the asteroid is classified as a potentially hazardous asteroid.

With an estimated diameter of about 660 meters (2,200 feet), it is larger than many other asteroids and is classified as a potentially hazardous asteroid due to its size and orbit.

Its orbit is elliptical, and it takes about 3.31 years to orbit the sun. When it is closest to the Earth, it is less than 0.65 astronomical units from the Earth, about 97 million kilometers.

Although it has never been seen since its discovery, scientists have calculated that the probability of it hitting Earth on December 14, 2113 is very low, about one in 1.8 million.

If it collided with our planet, the energy released would be equivalent to detonating about 30 billion tons of TNT, highlighting the importance of monitoring such objects for potential threats.

7) 2007 FT3

2007 FT3 is another asteroid classified as potentially hazardous due to its size and orbit around the Sun. It has a diameter of about 340 meters (1,115 feet).

The asteroid was discovered in March 2007 by astronomers from the Catalina Sky Survey in Arizona and is dangerous because of its close proximity to Earth.

Although 2007 FT3 does not currently pose a threat to Earth, its potential for a future collision with Earth could be a cause for concern if not properly monitored.

The asteroid’s orbit passes close to Earth every few years, so astronomers use advanced telescopes and computer models to track its trajectory.

8) Chicxulub Impactor

  • Area: about 10-15 km
  • Mass: Estimated to be several trillion tons

The Chicxulub impactor is one of the most significant asteroids in Earth history, best known for causing the mass extinction event that wiped out the dinosaurs about 66 million years ago.

The asteroid, estimated to be between 10 and 15 kilometers wide, struck what is now Mexico’s Yucatán Peninsula, creating a massive crater more than 150 kilometers in diameter.

The energy released by the impact was equivalent to 72 trillion tons of TNT, resulting in catastrophic consequences.

It triggered massive wildfires, tsunamis and a “nuclear winter” effect, blocking out sunlight for years and disrupting the climate and food chain.

This event caused the extinction of about 75% of species on Earth. The asteroid is believed to have come from the outer solar system, specifically a carbonaceous chondrite.

9) 7482 (1994 PC1)

  • Area: 1.1 km (1,100 m)
  • Mass: Estimated to be several million tons

7482 (1994 PC1) is a striking near-Earth object with a diameter of about 1.1 kilometers (about 3,450 feet). It is larger than 99% of known asteroids and comparable in size to iconic buildings such as the Golden Gate Bridge.

The asteroid was discovered in 1994 and is classified as a “potentially hazardous asteroid” because its orbit intersects with Earth. NASA and other space agencies closely monitor the asteroid to assess the risk it may present during future close approaches to Earth.

7482 (1994 PC1) flew safely past Earth on January 18, 2022, at a distance of about 1.2 million miles, more than five times the distance between the Earth and the Moon.

Continuous observations help ensure that any potential threats are detected in advance so that appropriate planetary defense strategies can be developed if necessary.

10) (46610) points

  • Size: Estimated 1.0 x 10^12 kg
  • Mass: Equivalent to approximately 2.2 billion pounds

(46610) Besixxduzi is a notable asteroid, primarily because it is classified as a potentially hazardous object due to its size and orbit.

The Bessiex Dozer asteroid was discovered in 1999 by astronomers from NASA’s Jet Propulsion Laboratory Near-Earth Object Program. It is about 1 km in diameter and has an orbital period of about 3.5 years.

While it does not currently pose an imminent threat to Earth, its classification draws attention because even an asteroid can cause significant damage if it collides with our planet.

The name “Bésixdouze,” derived from the French for “twelve,” reflects the date of its discovery — Dec. 12 — while also highlighting the importance of international collaboration in tracking NEOs.

Other Hazardous Asteroids in History

11) 2001 WN5

Size: About 0.9 km (about 900 m) in diameter

Mass: Estimated to be several million tons, but specific figures are usually not given in the literature

2001 WN5 is classified as a potentially hazardous asteroid because its orbit intersects with Earth’s. It was discovered on November 20, 2001, and has been closely monitored by astronomers.

NASA’s Jet Propulsion Laboratory (NASA JPL) has designated 153814 (2001 WN5) as a “potentially hazardous asteroid,” an asteroid whose orbit intersects Earth’s and is expected to pass close to Earth.

2001 WN5 orbits the Sun every 818 days (2.24 years), with a minimum distance of 0.91 AU and a maximum distance of 2.51 AU. Its diameter is about 0.9 km, larger than about 97% of asteroids, but smaller than large asteroids, and its size is comparable to the Golden Gate Bridge.

2001 WN5 rotates on its axis once every 4.25 hours. The asteroid will approach Earth on June 26, 2028, at a distance of about 0.65 Earth-Moon distances (about 250,000 km).

This close encounter provides an opportunity for further observation and research to better understand its characteristics and potential risks.