SPACE ROCKS collide with Earth’s ambiance on a regular basis. The overwhelming majority are too small to do any injury, however the threat of a bigger asteroid (or comet) wiping out a metropolis is one which area companies world wide are taking severely. The primary purpose of such would-be planetary defenders is detection: discovering all objects able to wreaking such injury and confirming that they don’t seem to be on a collision course with Earth. The opposite purpose is testing applied sciences that would both destroy such asteroids or else, extra plausibly, deflect them away from the planet.
