In 2002, an asteroid 150 to 360 ft (45 to 110 m) in diameter passed within 75,000 mi (121,000 km) of Earth—about a third of the distance to the Moon. Asteroids in similar orbits have struck Earth in the past. For that reason, scientists are currently developing a number of strategies by which near-Earth objects could be vaporized or diverted. These include the use of nuclear weapons and so-called gravitational tractors. When is the next near-Earth object expected to closely approach our planet? Discuss
Source: The Free Dictionary