What factors determine the impact of the asteroid?

The most important factor determining the damage to asteroid impact is the energy it releases after impact. This is calculated by multiplying half of the asteroid mass by a square of its speed. The typical range of asteroid speeds is relatively limited - most of the measured values ​​are between 12 and 20 km/s (7.5 - 12.4 miles/s). Comets are much faster and in the range of 50 to 70 km/s (31 - 43.5 miles/s).

Yet asteroids lack speed, they are equal to density - while the comets are supposed to consist of mostly ice, with a density of only 1000 kg/m 3 , asteroids made of solid rocks have a density of about 3 It is believed that asteroids with a diameter diameter diameter enter the Earth's atmosphere about once a month, leaving 100 ft (30 m) craters after their furrow. Asteroids with a kilometer diameter impact only once every million years, release up to 100 gigatons TNT, 200 times stronger than the strongest nuclear weapon ever tested. Such an impact would break glass windows up to 500 km away, and left the crater 20 km (12 miles). The greatest impact of the asteroid over the last 4 billion years has been considered an asteroid that created the Crater Vredefort in South Africa, with a diameter of about 20 km (12 Mi).

Large asteroids cause damage in one of the three ways: the initial explosion of an airuder thermal wool that can be strong enough to burn forests; Eject that can bathe ODLasti about the size of the continent in magma and blocking from the sun as a result of soot of particles in the upper atmosphere. The last factor is the most term for life, because without photosynthesis, the collapse of food chains and only decomposition and gadgets could survive for more than ten years. In the case of impact with asteroids over 20 km (12 million), scientists believe that all complex life (including all animals and higher plants) would be erased, leaving anything but microbes, similar to the Earth situation for about a billion years.