Asteroid 2024 YR4 currently has a 2.6 per cent chance of hitting Earth on 22 December, 2032, making it the biggest extra-terrestrial threat in more than two decades.

The threat posed by the space rock, estimated to be between 40 and 90 metres in diameter, is the highest ever recorded for an object of its size.

The space rock, known as asteroid 2024 YR4, reached its highest ever impact probability of 3.1 per cent – or a one-in-32 chance – yesterday, but new data has led the space agency to reduce its impact risk.