Fact/Fiction: Are asteroids really going to destroy the Earth?

How it was told

Climate change and on-Earth matters are dominating the headlines – but in some corners of the internet eyes have turned to the world-ending threat lurking in space.

If you’ve seen classic Bruce Willis film Armageddon, you’ll be well aware of the threat they pose but recent stories have warned of the world-ending impact that the space rocks could have in real life.

The Express website’s coverage on the subject has been intensive. Take the warning: “Asteroid terror: Nasa told Earth will ‘100 per cent be hit’ by killer space rock by expert” or the inevitability of the news in the headline: “Asteroid panic: We’re sitting ducks! Experts warn of apocalyptic asteroid strike”.

The headline: “Asteroid warning: Universe is trying to ‘KILL US OFF’ – warning” also came from the Express, while another story also “Asteroid panic: ‘Most devastating natural disaster known to man!’ Shock Nasa warning”. And those stories were over just a couple of days last week.

Other outlets have also covered the asteroid threat, for example, The Daily Mirror’s “Nasa preparing for ‘God of Chaos’ asteroid due to whizz past Earth in 10 years”. Metro, The Sun and The Independent also reported the story.

But is it “100 per cent” that the planet will be hit by an asteroid and is it likely to have world-ending consequences?

Facts. Checked

It is “100 per cent likely” that we will be hit by an asteroid – but the risk of a world-ending asteroid striking the Earth is minimal.

An asteroid is defined as a relatively small, inactive, rocky body orbiting the sun. Because the Earth also orbits the sun in a predictable fashion, it possible for space experts to predict their future path very accurately.

Nasa’s NEO Observations Program estimates that they have found more than 95 per cent of near-Earth asteroids. You can see Nasa’s Sentry: Earth Impact Monitoring data online to judge for yourself, complete with a potential chance of impact.

That means it is very unlikely that an asteroid that has the potential to strike the Earth and cause an extinction level event will appear out of nowhere.

For the ‘God of Chaos’ stories, those referenced an asteroid as wide as the Eiffel Tower is tall, known as 99942 Apophis. Experts were able to predict that it would narrowly miss Earth by 19,000 miles.

But the Earth does get bombarded with 100 tons of space debris every day, according to Nasa, most comprising of dust and sand-sized particles. As for the bigger stuff, Nasa says that once a year an asteroid the size of a car enters our atmosphere and burns up before hitting the surface, as is the case for any space rock under 82 feet.

They also report that rocky meteoroids – a small particle from a comet or asteroid orbiting the sun – larger than that size but smaller than half a mile would cause local damage and any rock larger than that has the potential for worldwide effects.

Nasa says that once every 2,000 years a meteoroid the size of a football pitch hits Earth and causes significant damage, but an object large enough to threaten civilisation – see the dinosaurs – happens every few million years and the evidence is all around with craters.

So the risk of us being wiped out by an asteroid is incredibly low from day to day – certainly not warranting the barrage of sensational articles that the issue currently demands.

However, Nasa does warn that the Armageddon and Deep Impact Hollywood solution of using weapons on a rock on course to hit the Earth would not be possible – no known weapon system could keep up with the velocity of an asteroid which, travels at 12 miles
per second.

Image: Miles Cole