02 May 2019
Asteroid Attack
The universe strikes back.
By Neil Tidmarsh
Oh no, not another apocalypse looming on the horizon!
As if climate change (Extinction Rebellion, Greta Thunberg) and the decay of democracy (almost 60% of Americans, over 50% of Britons and over 40% of Germans are dissatisfied with democracy, according to a survey recently published by the Pew Research Centre in the US) and the rise of the robots aren’t enough to worry about, we were told this week that another doomsday scenario – asteroid strike – is rather more likely than we thought.
The head of Nasa, Jim Bridenstine, addressing a seminar in Maryland on planetary defence, announced that seven hundred new asteroids (lumps of rock – too small to be classed as planets – left over from the creation of our universe and orbiting our sun) have been discovered in the last year. This takes the number of known asteroids up to 20,000, which means we can expect a collision every 60 years, according to Mr Bridenstine.
There have been three in the last century: two in Russia (1908 and 2013) and one in Brazil (1930). These were small asteroids, but the last one damaged thousands of buildings and injured thousands of people around the town of Chelybinsk, even without hitting us whole – it exploded when it was 14 miles away from Earth. Imagine what a really big one could do (1000 of them are over a kilometer in diameter). Long ago, one of them cleared the dinosaurs out of the way for us; could another one – not so far away in the future – clear us out of the way for… something else, the evolution of the cockroach into an advanced and intelligent insect species, for instance?
This week, scientists from bodies such as Nasa and the European Space Agency are modelling the approach of an asteroid heading this way (with a 1% chance of hitting the Earth in eight years time) and examining what we could do about it in the way of deflection or redirection. Nasa hopes to send an actual mission into space in three years time to try such tactics for real; a craft will be launched from a rocket and crashed into an asteroid in an attempt to alter its orbit.
Interestingly, the one thing the scientists recommend we don’t do is drop a bomb on it in an attempt to blow it up (which would only target us with lots of smaller rocks rather than one big rock – like firing a shot-gun rather than a rifle, as it were). Hang on, isn’t that more or less what a Japanese spacecraft did last month? Jaxa – the Japanese Aerospace Exploration Agency – reported that the unmanned Hyabusa 2 probe dropped a powerful explosive on the asteroid Ryugu and blasted a crater into its surface. Was that wise? Ok, it happened 187 million miles away from Earth and scientists will learn a lot about the origin and nature of asteroids (and of the universe) from the material collected; but it seems such a hostile, aggressive and violent act – no wonder an apparently enraged solar system is preparing to strike back by hurling huge lumps of rock at us. It’s easy to imagine that it’s a sentient being and that it’s angry with homo sapiens.
And angry with reason; only a week or two ago, an Israeli spacecraft (Beresheet, the first privately-funded lunar mission) crash-landed on the Moon, no doubt scattering debris across the planet’s pristine surface, like a drunk driver crashing his car in the middle of a national park. Its main engine apparently failed, and luckily it was unmanned, but the Moon can’t have been very happy about it. And a month before that, India tested its new anti-missile defence system by shooting down a satellite orbiting the earth 300km away in space. Prime minister Narendra Modi proudly announced “India has registered its name as a space power”, but the USA expressed its dismay and disapproval of the hundreds of thousands of metal fragments – dangerous to space stations and astronauts and their crafts – which the test has sent streaming through space. Again, space probably wasn’t too thrilled by it, either.
Perhaps the universe has seen what we’ve done to Earth and is determined to stop us from spreading out through our solar system before we can wreak the same destruction on more of its planets. A massive rock bowled at our base camp should do the trick.
