When the end of the world is nigh, do you head for the pub or the church?

Following the possible trajectory of 2024 YR4 – AKA the scariest asteroid ever detected – is it not for the nervous of disposition. Is it going to hit us, or not? Every day, a different answer.

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Last Tuesday, Nasa calculated it had a 3.1% chance of hitting Earth in 2032, and so some people set to worrying. Twenty-four hours later, the agency provided an update. New observations, made since the passing of the full moon, show it now has a 1.5% chance of impact. Time to exhale? Not necessarily.

The asteroid is estimated to be 40-90 metres wide, about the same size as a large building. If it does hit, and doesn’t splash down into the sea, it could decimate a city. Scientists calculate that its impact could be similar to that of the Tunguska asteroid, which flattened an area more than double the size of New York in Siberian forest in 1908. If it landed in central London, windows 20 miles away in Slough would be broken – an event that would exceed the wildest dreams even of John Betjeman, who once wrote a rather mean poem about the town.