Museum für Naturkunde Berlin: Effects of meteorite impacts

The effects of meteorite impacts depend on the composition of the impactor and its trajectory when entering the atmosphere. Large asteroids (>200 m for rocky composition, >50 m for iron composition) with a large impact energy experience little deceleration by the atmosphere and form large craters upon impact with a velocity of several km/s (the typical impact velocity before entering the atmosphere is 18 km/s). In case of smaller objects, depending on the material composition (iron or rock) and the energy of the object, a crater forms, a strewn field of several smaller craters occurs, or the body disrupts in the atmosphere generating a strong blast wave.

Predictions of the effects

When a small asteroid encountering Earth is detected, only little time might be available to predict the potential consequences. Sophisticated simulations of such impact scenarios with the help of computer models are computationally expensive and time-consuming. Such simulations on high-performance computers can last several weeks or months. If time is pressing alternatives are required to initiate mitigation measures. By means of a database composed of simple estimates and a large number of pre-processed simulations of probable impact scenarios the effects can be estimated within a few minutes. Such a database was generated within this project, and was integrated into a newly developed prediction software for ESA.