Will an asteroid ever slam into our planet, destroying life as we know it? This is how NASA breaks it down: Our planet is bombarded daily with as much as 100 tons of small particles, some just the size of a grain of sand. Then, an annual car-sized asteroid burns up in the Earth’s atmosphere, creating fireballs and inevitable reports of UFOs. Every 2,000 years or so, a “meteoroid the size of a football field” crashes into Earth, causing some major damage. Then, once every million years or so, a big asteroid collides with the Earth, threatening all life.
Luckily, NASA has its eyes — and telescopes, satellites and space fliers — trained on the various asteroids of our solar system. The space agency tracks and “characterizes” objects that may potentially harm our planet with its Near-Earth Object Observations Program, also known as Spaceguard. We’ve compiled several images from NASA and elsewhere of notable neighboring asteroids. (Text: Katherine Butler)