# Could an asteroid hit Earth?

> Will an asteroid hit Earth? Small ones do every year, big ones very rarely. NASA's odds by size, how risk lists work, and the Apophis pass of 13 April 2029.

HTML: https://www.theuniversecounts.com/solar-system/asteroids-and-comets/could-an-asteroid-hit-earth

Numbers as of 2026-11-04 16:50 UTC. Live ones keep changing on the HTML page.

Will an asteroid hit Earth? Small ones do, all the time, and burn up harmlessly. Big ones are rare: NASA estimates a 140-metre asteroid hits about once every 20,000 years. No known large asteroid has a significant chance of hitting us in the next century. The next famous visitor, Apophis, will pass safely on 13 April 2029. The clock above counts down to it.

- Time until asteroid Apophis passes closest to Earth: 891d 04h 55m 01s
- Highest Torino scale rating of any asteroid on NASA's Sentry list: 0
- Time since NASA's DART spacecraft struck the asteroid Dimorphos: 4y 38d 17h
- Number of known near-Earth objects (asteroids and comets): 43,065

## Rocks fall on Earth all the time

Space is not empty. Dust and small stones hit our atmosphere every day, and we see them as shooting stars. Larger rocks are rarer, and the larger they are, the rarer they get.

A rock about 10 metres across arrives about once every 10 years. It makes a brilliant fireball and a bang, and can break windows. One about 50 metres across comes every between 1,000 and 1,500 years and could flatten a city.

The truly dangerous ones are rarer still. A 1-kilometre asteroid hits about once every between 520,000 and 700,000 years. One 10 kilometres across, like the one that ended the dinosaurs, comes every between 100 million and 120 million years. These are averages, not a timetable: Earth is never "due" for one.

## How the risk lists work

When a new asteroid is found, its orbit is fuzzy at first. NASA's Sentry system and ESA's own risk list run that fuzzy orbit forward a hundred years. If any possible path touches Earth, the asteroid goes on the list with a small chance of impact.

As of 4 November 2026, Sentry lists 2,230 asteroids. The highest rating among them on the Torino scale, which runs from 0 (no hazard) to 10, is 0.

More sightings shrink the fuzz. Usually Earth then falls outside it, and the chance drops to zero. That happened with 2024 YR4. In early 2025 it briefly had a small chance of hitting us in 2032. More sightings ruled out an impact in 2032, and Sentry removed it in March 2026. Its pass on 22 December 2032 now misses both Earth and the Moon in NASA's data.

## Apophis, 13 April 2029

Apophis is a large asteroid. Soon after it was found, it briefly looked like it might hit us. Better measurements removed it from the risk list in 2021: NASA says it poses no risk for at least 100 years.

On 13 April 2029, it will pass about 38,000 kilometres from Earth's centre. That is closer than the satellites in geostationary orbit, about 36,000 kilometres up. It is about 10 times closer than the Moon.

## We have already moved an asteroid

On 26 September 2022, NASA's DART spacecraft flew into Dimorphos, a small moon of the asteroid Didymos. Neither threatened Earth. The test was whether a spacecraft could push one.

It could. DART shortened Dimorphos's orbit by 32m 00s. That is a small change, but given years of warning, a small push is enough to make an asteroid miss.

## What we have found, and what we haven't

Surveys have found more than 90% of the near-Earth asteroids larger than 1 kilometre, the ones that could cause global harm. None of them is on a path to hit us.

Smaller ones, around 140 metres, are harder to see, and many are still unfound. That is the work of the Rubin Observatory and NASA's planned NEO Surveyor telescope. We are the first living things on Earth that can see a rock coming, years ahead, and do something about it.

## FAQ

### How likely is an asteroid to hit Earth?

Small ones hit often: a 10-metre rock about once every 10 years. Big ones are very rare. A 1-kilometre asteroid hits about once every between 520,000 and 700,000 years, and none we know of is on course for us.

### What will happen on 13 April 2029?

Apophis will pass about 38,000 kilometres from Earth's centre, inside the ring of geostationary satellites. It will not hit us.

### Will 2024 YR4 hit Earth or the Moon?

No. More observations ruled out an Earth impact in 2032. NASA removed it from its risk list in March 2026, and its 2032 pass misses the Moon too.

### What is the Torino scale?

A 0 to 10 rating of how much attention an asteroid deserves. 0 means no hazard. As of 4 November 2026, the highest on NASA's list is 0.

### Can we stop an asteroid?

NASA's DART mission showed that a spacecraft can nudge an asteroid. It shortened a small asteroid's orbit by 32m 00s.

## Related

- [Asteroids passing Earth](https://www.theuniversecounts.com/solar-system/asteroids-and-comets/asteroids-passing-earth.md)
- [How far away is the Moon right now?](https://www.theuniversecounts.com/earth-and-moon/the-moon/how-far-is-the-moon.md)
- [Halley's Comet](https://www.theuniversecounts.com/solar-system/asteroids-and-comets/halleys-comet.md)

If you could watch Apophis cross the sky in 2029, who would you want beside you?

## Sources

- Apophis's closest distance from Earth's centre on 13 April 2029 (Measured): [NASA: Asteroid Apophis Facts](https://science.nasa.gov/solar-system/asteroids/apophis/)
- Asteroids on NASA's Sentry impact-monitoring list (Measured): [NASA JPL CNEOS: JPL Sentry API](https://ssd-api.jpl.nasa.gov/sentry.api)
- Average time between impacts on Earth of asteroids about 10 kilometres across (Estimated): [NASA: Asteroid Facts](https://science.nasa.gov/solar-system/asteroids/facts/); [National Academies of Sciences, Engineering, and Medicine: Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes, Table 1.1 (doi:10.17226/25476)](https://www.nationalacademies.org/read/25476/chapter/3)
- Average time between impacts on Earth of asteroids about 10 metres across (Estimated): [NASA: Asteroid Facts](https://science.nasa.gov/solar-system/asteroids/facts/)
- Average time between impacts on Earth of asteroids about 1 kilometre across (Estimated): [NASA: Asteroid Facts](https://science.nasa.gov/solar-system/asteroids/facts/); [National Academies of Sciences, Engineering, and Medicine: Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes, Table 1.1 (doi:10.17226/25476)](https://www.nationalacademies.org/read/25476/chapter/3)
- Average time between impacts on Earth of asteroids about 50 metres across (Estimated): [NASA: Asteroid Facts](https://science.nasa.gov/solar-system/asteroids/facts/); [National Academies of Sciences, Engineering, and Medicine: Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes, Table 1.1 (doi:10.17226/25476)](https://www.nationalacademies.org/read/25476/chapter/3)
- Height of geostationary satellites above Earth's surface (Measured): [NASA: Asteroid Apophis Facts](https://science.nasa.gov/solar-system/asteroids/apophis/)
- Highest Torino scale rating of any asteroid on NASA's Sentry list (Measured): [NASA JPL CNEOS: JPL Sentry API](https://ssd-api.jpl.nasa.gov/sentry.api)
- How much DART shortened Dimorphos's orbit around Didymos (Measured, with error): [NASA: Double Asteroid Redirection Test (DART)](https://science.nasa.gov/planetary-defense-dart/)
- Number of known near-Earth objects (asteroids and comets) (Measured): [NASA JPL: JPL SBDB Query API, near-Earth objects](https://ssd-api.jpl.nasa.gov/sbdb_query.api?fields=pdes&limit=1&sb-group=neo)
- Share of near-Earth objects larger than 1 kilometre already discovered (Estimated): [NASA JPL CNEOS: Frequently Asked Questions (FAQ)](https://cneos.jpl.nasa.gov/faq/new.html)
- The Moon's average distance from Earth (Measured): [NASA: Moon Facts](https://science.nasa.gov/moon/facts/)
- Time since NASA's DART spacecraft struck the asteroid Dimorphos (Measured): [NASA: DART (Double Asteroid Redirection Test)](https://science.nasa.gov/mission/dart/)
- Time until asteroid Apophis passes closest to Earth (Measured): [NASA: Asteroid Apophis Facts](https://science.nasa.gov/solar-system/asteroids/apophis/)