Impacts with space debris are truly spectacular events, as the size of the object belies the devastation they can wreak. Not only does an impact event obliterate the the area around it, rock can also be thrown high into the air and particularly large ones can change the very evolution of life.
History
After the birth of the solar system 4.6 billion years ago, its planets saw many planet-sized collisions. Mercury was hit by an object that formed the 1550km Caloris basin. Venus suffered a glancing blow that was enough to make it spin the other way. Mars saw an impact that created a crater the size of half the planet's surface.
