Asteroids are more dangerous than lightning!

If you’re British, you are more likely to die from an asteroid strike than a lightning bolt! That might sound strange, given the relative frequency of thunderstorms as against large lumps of space rock striking Planet Earth, but the statistics bear this out.

Strikes by dangerous Near Earth Objects (NEOs) occur on average once every million years, with “danger” being reckoned as applying to a lump of rock more than 2 kilometres (1.2 miles) in diameter. Were one to strike, the likely death toll has been estimated at around one billion. This means that an individual’s chance of dying from this cause in any given year is around one in six million.

The chance of being struck by lightning in the UK, and dying as a result, is around one in ten million. In other words, the odds are far better than those for an asteroid strike!

There are parts of the world where the odds might not be so advantageous, due to the UK’s relative freedom from severe weather events – the Amazon rainforest, for example, gets many more thunderstorms than Bognor Regis. In total, lightning strikes the surface about 50 times a second, but the strikes are not evenly distributed across the globe.

Another factor to bear in mind is that most people take steps to avoid being caught in thunderstorms, so the fact that coastal areas of the UK get an average of two lightning strikes per square kilometre per year should not cause too much alarm – it is natural to check the weather forecast before setting off on a clifftop walk!

Another precaution one can take is not to stand in the open in a thunderstorm holding a lightning conductor, such as a golf club or carbon-fibre fishing rod. Failure to observe this simple precaution might be behind the fact that men are six times more likely to be struck by lightning than women! 

The actual annual death toll from lightning strikes in the UK is between three and six. And the figure for asteroid fatalities? OK – zero this year, and last year, and the one before that … But it only takes one direct hit and we’ll all suddenly become very unfortunate statistics!

© John Welford