An asteroid that was first spotted and Monday and passed the Earth at a distance equivalent to one-third the Earth-Moon separation yesterday was captured on film by a team of astronomers from Italy.

The asteroid, now known as 2010 AL30 was discovered by the LINEAR survey of MIT's Lincoln Laboratories on 10 January, and orbital calculations showed that it would make its closest approach to Earth at 1246 GMT on 13 January, showing that sometimes there really isn't much warning time of such an event.

With a one-year orbital period around the Sun, the object was initially thought to be a manmade rocket stage – and there is still some speculation that it might be the spent rocket booster from ESA's Venus Express mission – but NASA's Near Earth Object office says that since its orbit reaches from the orbit of Venus out to nearly the distance of Mars' orbit, crossing the Earth's orbit at a very steep angle, and has not approached the Earth for the duration of the Space Age, it is most likely an asteroid.

More detailed analysis should give up the object's mysterious nature, but either way, the 10-15 metre wide body did not threaten the Earth in any way. Indeed, rocky asteroids of this size frequently burn up in the Earth's atmosphere before they are able to reach the ground and two million such objects are thought to exist in near-Earth space.

In 2029, an asteroid known as Apophis will pass by the Earth three times closer than 2010 AL30. Read more about Apophis here.