Astronomy, Armageddon | featured news

A small asteroid passed within the moon's distance from the Earth on Wednesday morning, and another will do likewise later in the day, space watchers say.

NASA may appear to have its pick of thousands of known asteroids for a manned mission, but only two are good targets within the next 20 years. An asteroid mission requires a large-enough destination that astronauts could reach within a few months of launch from Earth, says Lindley Johnson, head of NASA's Near-Earth Object program in Washington. Other limits to such an ambitious undertaking include the viewing range of ground-based telescopes.

Russia's space chief said Wednesday his agency will consider sending a spacecraft to a large asteroid to knock it off its path and prevent a possible collision with Earth.