Tiny to Vast
Impact Effects CalculatorMapLibre · Physics model

Asteroid Impact Simulator

Pick an impact site, choose an asteroid, and map the crater, fireball, thermal burns, and blast zones with the Collins, Melosh & Marcus model.

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One more perspective

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Fig. 01

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Fig. 02

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Asteroid Impact Simulator

Map the crater, fireball, and blast zones of an asteroid impact

Drop a meteor anywhere on the interactive map and watch its estimated effect zones spread. Diameter, speed, angle, and composition feed the same atmospheric entry, crater, thermal, blast, and seismic model used by the legacy tool.

How to use the impact map

  1. Tap the map, use the keyboard target, or pick a city.
  2. Set diameter, speed, angle, and composition, or load a preset.
  3. Read crater, fireball, burn, and blast radii on the map and results.
  4. Change the population-density assumption or export a map image.

How the effects are calculated

The simulator implements the Earth Impact Effects Program of Collins, Melosh, and Marcus (2005). It models atmospheric breakup first, then applies crater scaling, fireball thermal radiation, seismic energy, and blast overpressure.

What the effect zones mean

Rings extend from the impact point through the crater and fireball, thermal burn zones, and 20, 5, and 1 psi air-blast zones. They are modeled educational estimates, not predictions for emergency planning.

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Asteroid impact FAQ

What does an asteroid impact simulator calculate?

It estimates impact energy in megatons of TNT, crater size, fireball radius, thermal burn zones, air-blast overpressure rings, peak wind speed, and seismic magnitude from the size, speed, angle, and composition you choose.

How is asteroid impact energy calculated?

Impact energy is kinetic energy: one half times mass times velocity squared. Mass comes from diameter and density, so an iron asteroid is much heavier than an icy body of the same size. One megaton of TNT is 4.184 × 10^15 joules.

What is the difference between an airburst and a crater-forming impact?

Small or low-density asteroids can break apart and release their energy in the atmosphere, so no crater forms. Larger or denser bodies can retain enough speed to reach the surface and excavate a crater.

How big does an asteroid need to be to cause mass extinction?

The Chicxulub impactor associated with the end-Cretaceous extinction is estimated at roughly 10 kilometres across and released on the order of tens of millions of megatons of TNT. Events that large are extremely rare.

Which model do the impact effects use?

The calculations follow the Earth Impact Effects Program published by Gareth Collins, Jay Melosh, and Robert Marcus in 2005, combining atmospheric entry, crater scaling, fireball thermal radiation, and blast data.

How accurate is an asteroid impact simulation?

The results are order-of-magnitude estimates with large uncertainties, especially for airbursts and very large impacts. The model assumes a land target and omits ocean impacts, tsunamis, ejecta fallout, and long-term climate effects.

Educational estimates only; the model does not predict a specific event.