Just 1% of the asteroids that threaten to wipe out life on Earth are on NASA’s maps. Some scientists want more resources to deal with them. Is this the biggest threat to life on our planet?
A man 40 miles away was knocked off his chair. Eight hundred square miles of forest were destroyed — meaning 80m trees were knocked over. Many animals were killed.
Fortunately, no people were killed when a 100-metre meteor struck in a remote part of Siberia at 7:17am on June 30th 1908. But locals were so shocked they believed a god had cursed the area.
Some view the prospect of a similar collision with dark humour. In a poll last month, 13% of Americans said a meteor annihilating life on earth would be preferable to electing either Hillary Clinton or Donald Trump as president. But a group of scientists are now calling for a more serious response, including a one hundredfold increase in the asteroid discovery rate within a decade.
Apollo 9 astronaut Rusty Schweickart warns that space rocks have struck Earth ‘millions of times’ before. ‘It will also happen in the future. But if we humans do our job correctly this will never happen again.’
About 100 tonnes of meteroids enter the Earth’s atmosphere each day and become meteors. Most burn up harmlessly, but records suggest they killed people in ancient China. And as recently as 2013, a meteor exploded above Chelyabinsk in Russia, injuring 1,000 people.
More concerningly, NASA estimates that 2,100 asteroids larger than 1km pass between the sun and the edge of Earth’s orbit. A collision with one of them could degrade the global climate, destroy crops and threaten everyone on Earth. The largest known asteroids are around 8km wide — and many cometscould do similar damage.
Efforts to mine asteroids could help to find them, while groups like the B612 Foundation are trying to develop the technology needed to deflect them. But Schweickart says NASA is not tracking 99% of those which could wipe out a city on Earth — or 90% of those which could devastate countries.
Other factors could also cause the mass extinction of humanity: for example catastrophic climate change, nuclear war or artificial intelligence. But are rocks from space the most worrying threat of all?
We should invest more time and money to tackle it, say some. We know very little about asteroids, so we are unprepared. Unlike other threats, a collision is mathematically certain at some point without our intervention. It could happen, unannounced, at any time — whereas other threats are more foreseeable.
That is an over-reaction, others respond. The catastrophic strike which wiped out the dinosaurs happened 65m years ago; such events are vanishingly rare. The human race is much more likely to be destroyed by its own hand, so that is where it should focus its attention. Our fascination with asteroids is not rationally justifiable.