The near-Earth asteroid 99942 Apophis makes a close pass
This rocky body – measuring 270 metres across – had a 1 in 45,000 chance of hitting the Earth on this date.
With a mass of 21 billion tons, and a speed of 30 kilometres per second, it could release 880 megatons of energy on impact. By comparison, the largest nuclear bomb ever tested, the Tsar Bomba, had a yield of around 50 megatons: more than ten times the amount of all the explosives used in World War II combined.
Such an impact might cause tens of millions of casualties if occurring in a heavily populated region, while an impact off the West Coast of the USA could produce a devastating tsunami.
Luckily the asteroid only grazed the Earth’s atmosphere leaving behind heavy amounts of particulate ash contributing to the already poor climate situation.