03 February 2012 Asteroids in space When asteroids approach
Earth, they typically do so at a speed of between five and 30
kilometres per second. Thousands of near-Earth objects (NEOs)
have been discovered in the past 20 years. The consequence of an
asteroid's collision with Earth are clear; the 1200-metre
diameter Barringer Crater in Arizona is the result of an impact
with an asteroid 50 metres in diameter. The Tunguska region in
Siberia In 1908, an asteroid explosion uprooted millions of
trees in Siberia's Tunguska Region. Russian Academy of
Sciences/L. Kulik. NEOShield - hunting for near-Earth asteroids
and comets NEOShield, an international cooperation being led by
DLR, will investigate the properties of near-Earth objects and
develop a strategy to prevent collisions with Earth.
NASA/JPL/JHUAPL (Montage: DLR). International cooperation under
the leadership of DLR It is not entirely clear when exactly the
last major asteroid impact on Earth occurred. But there are
plenty of examples of impact craters, such