The most popular hypothesis which explain the dinosaur extinction is that Earth was hit by large asteroid 66 mln years ago, during the Cretaceous-Paleogene extinction event. It is considered that the asteroid had a diameter of 5 to 15 km (3-9 mi) and caused not only the extinction of the dinosaurs, but it also erased more than 50% of the living world on Earth then.
Not so long ago, in the middle of February, 2013, these space objects just slightly reminded us of how devastating they could be – an asteroid entered the atmosphere at speed of 18,6 km/s (41 000 mph or 66 960 km/h) and turned into the Chelyabinsk meteor, which exploded over the Chelyabinsk area in Russia. Nearly 7200 buildings were damaged and 1500 people were injured due to the explosion, which turned the Chelyabinsk meteor into a rain of thousands smaller bullets.
There’s no room for wondering why many scientists research the effect of possible impact between Earth and the thousands of asteroids that pass nearby. Frank Schäfer of the Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI in Freiburg, is one of these scientists. He is simulating impact with 100 m to 300 m long asteroids. For that purpose he and his team attach materials that resemble properties of various types of asteroids – thick quartzite, lighter and porous sandstone or airy concrete, to a pendulum and after that they throw aluminum “bullets” at the artificial meteorites. What they discovered is that the aluminum bullets were more effective against materials with higher density and almost did not caused effect over porous materials.
The purpose of these experiments is to test a possible way of redirecting asteroids which endanger Earth. This way consists of causing an impact between space probe orbiting around Earth and the approaching asteroid. The aluminum projectiles reached speed of 10 km/s which gave hope to the researchers that such model is possible.
SOURCE: [fraunhofer.de]
