An asteroid half the size of a football field has passed closer to Earth than any other known object of its size.

Asteroid 2012 DA14, discovered just last year, passed about 27,700km from Earth around 7.30pm this evening, closer than the networks of television and weather satellites that ring the planet.

Scientists at NASA's Near-Earth Object program at California's Jet Propulsion Laboratory estimate that an object of this size makes a close approach like this every 40 years. The likelihood of a strike is once every 1,200 years.

Asteroid 2012 DA14, as it is called, was too small to see with the naked eye even at its closest approach over the Indian Ocean near Sumatra.

Most of the solar system's asteroids are situated in a belt between the orbits of Mars and Jupiter, and remain stable there for billions of years.