← All scenarios

Spaghetti Scenarios · Global risk

Asteroid impact ≥ 1 km

An asteroid one kilometer or larger strikes Earth and causes effects across the planet: fires, darkness and a cooling that ruins harvests. It is a real but very rare risk, and it is the only catastrophic one against which a proven defense already exists: an asteroid can be deflected if it is detected in time.

We already know almost all the asteroids capable of a global catastrophe, and none threatens us; many of the medium-sized ones are still to be found.

Catalog of near-Earth objects

42,616

known near-Earth asteroids as of October 5, 2026. Of these, 879 are 1 km or larger and 11,712 are 140 meters or larger.

▲ In 2015, 13,690 were known; today, more than triple

Uncataloged objects detected

3,241

new near-Earth asteroids were discovered in 2025, a record. Only 2 were 1 km or larger: almost all the big ones are already in the catalog.

▲ In 2015, 1,585 were discovered; in 2025, double that

Results of deflection missions

33 min

is how much the DART spacecraft shortened a small asteroid's orbit by crashing into it in 2022: 25 times more than the minimum sought. The Hera spacecraft will arrive in November 2026 to study the result.

▲ First successful test of deflecting an asteroid

1 in 500,000probability per year
~0.02%probability between 2025 and 2100

Cumulative probability of it happening

Vertical axis zoomed in: everything stays below 1%
Remote (less than 1%)0%0.005%0.01%0.015%0.02%20252040206020802100today0.005%
Year: 2050

Near-Earth asteroids we already know

Cumulative total of discoveries. Move the slider to see each year. The line for the large ones barely grows: few are left to find.

010,00020,00030,00040,00019992005201020152020202642,61611,712879
  • All sizes42,616asteroids in 2026
  • 140 meters or larger11,712asteroids in 2026
  • 1 km or larger879asteroids in 2026

Totals at the end of each year; 2026 through October 5.

How many have we found?

Share found in each group, based on estimates of how many exist. The white line marks the goal set by the U.S. Congress: find 90% of those 140 meters or larger.

1 km or larger (global effects)~95%
About 1,000 in total; none is a current threat.
140 meters or larger (regional damage)~47%
11,712 known out of an estimated 25,000.

The first deflection test

33 minwas cut from the orbit of the asteroid struck by DART (from 11 h 55 min)
73 swas the minimum change sought: it was exceeded 25 times over
3.1%was the peak probability of a ~60 m asteroid striking in 2032 (February 2025)
0risk today: ruled out for Earth and, since March 2026, for the Moon as well

Monitoring and planetary defense

  1. 2022DART crashes into a small asteroid (September 26) and changes its orbit: the first planetary defense test.
  2. 2024The European Hera spacecraft is launched (October 7). In December an asteroid about 60 meters across is discovered with a risk of impact in 2032.
  3. 2025That asteroid reaches a 3.1% impact probability (February 18) and a few days later is ruled out for Earth.
  4. 2026Observations from the James Webb telescope also rule out its impact with the Moon (March). Vera Rubin announces more than 11,000 new asteroids, 33 of them near Earth (April), and begins its ten-year survey (June).
  5. Today · October 2026
  6. 2026Hera reaches the asteroid struck by DART (November).planned
  7. 2027Launch of the NEO Surveyor space telescope, designed to search for dangerous asteroids (no earlier than September).planned

Asteroid impact ≥ 1 km

Impact
Catastrophic (5)
Probability
Remote (1)
Over the horizon
~1 in 500,000 per year → ~0.02% in 2025–2100
Timeframe
Centuries–millennia
Score
5
Confidence
High
Reversibility
Irreversible on a human scale
Classification
Astronomical

Signals to watch

  • Catalog of near-Earth objects
  • Uncataloged objects detected
  • Results of deflection missions

Possible human action

  • Continuous astronomical monitoring
  • Deflection missions
  • Warning cooperation