An asteroid about 100 metres in diameter and racing at 24 kilometres a second has just missed the Earth.

The rock, called Asteroid 2019 OK, sped by our planet at 11.22am on Thursday, passing within about 70,000 kilometres – which is a long way away but closer to us than the moon’s orbit.

The asteroid passed close by on Thursday morning. Credit:NASA

Due to the trajectory of the asteroid – flying towards us from the direction of the sun – astronomers had no warning it was headed our way.

It is the largest rock to fly at such close quarters to the Earth this year, and possibly for many years.