So who cares if the sky is falling?

Very few in the politically hamstrung world of science, despite last week's discovery of a celestial catastrophe 65 million years ago, says Oliver Morton

It happened 65 million years ago, and it could happen again. Something pretty big and moving extremely fast hit the earth very hard indeed. Waves to dwarf skyscrapers criss-crossed the oceans and swamped the land. An atmosphere that had caught fire rained acid. Tectonic spasms ran up the spines of the continents. Billions of tonnes of rock and mud were thrown into space, and as they re-entered the atmosphere, their heat set off fires around the world. The skies glowed dull red, then darkened to midnight black as an all but impenetrable pall of dust and smoke settled into the stratosphere. There was not another dawn for years.

The idea that an asteroid impact 65 million years ago killed off the dinosaurs and roughly three out of four other species then living is now firmly lodged in the scientific mind and the public imagination. The evidence for the impact is overwhelming. The huge crater it left has been discerned beneath thick sediments in Mexico, the mark of its tidal waves can be seen in the middle of America and its distinctive debris and ash has been found all over the world. The death of the dinosaurs doesn't keep resurfacing because there is a hot debate or a lively controversy; it does so because it's just such a cracking story. New wrinkles to the tale, such as last week's announcement of evidence for centuries of near-sterility in the oceans following the impact, get media attention simply because astronomy, dinosaurs and mayhem are the ideal ingredients for popular science.

But our fascination isn't quite that simple. There's something more to it: the worrying implication, raised half jokingly by the Trevor MacDonalds and Sue MacGregors when the science correspondent has done his bit, that it could happen again. This catastrophe was not a one-off. There have been many asteroid impacts in the history of the earth; left unchecked, there will be many more.

These impacts could kill billions of people, and you could be one of them. The risk of your dying in such an event is around one in 30,000, which, though small, is far from insignificant. It's certainly far greater than the chances of your winning the lottery. Like the destruction of the dinosaurs, this risk has slipped into the popular imagination, lubricated by documentaries and magazine covers. We all know of it, and we could, scientific opinion assures us, easily and cheaply do something about it. But we don't. It's a mistake that, while unlikely to prove tragic, reveals a lot about how science is used and what science means.

The truth of the matter is straightforward. The solar system is not just a neatly concentric set of planets. There are lots of smaller lumps of ice and stone and iron whirling around the sun, too. They hit the earth all the time, and they come in a range of sizes, the big ones proportionately rarer than the small. The vast majority are just pretty shooting stars - far too tiny to worry about. But watch these meteors for long enough and you will see some bigger ones. Watch for half a million years and you can expect to see one that outdoes a major nuclear war for nastiness, laying waste a continent, blacking out the sun for a year or more, blighting the world's crops.

If the risk of such an impact is 500,000 to one in a given year, then over a 70-year span, the cumulative risk to any individual of living through or dying in such an event is about one in 7,000. If such an impact leaves about 25 per cent of the earth's population dead, most of them through starvation, that gives any person a risk of about one in 30,000 during the course of an average lifetime. Some estimates make the risk smaller, and others make it larger, but that is a good average. It means that the huge unpleasantness of impacts offsets their great infrequency enough to make them roughly as dangerous as air travel, which entails a risk of about one in 20,000.

In the case of air travel, this is a level of risk people feel quite strongly about. On 13 February, President Clinton set a goal of reducing the risk of dying in an air crash by 80 per cent. Nasa, whose first A stands for aeronautics, and which thus has a thumb in the air-safety pie, will be spending about $100m a year on the project. Most people thought this investment quite wise, but a scientist called David Morrison raised an inquiring eyebrow.

Morrison, who enjoys the wonderful title "director of space" at Nasa's Ames Research Center in California, chaired a committee which produced a report in 1992 for the US Congress on the asteroid risk. Its advice was simple. There are probably a couple of thousand asteroids of the once- every-half-a-million-years, climatic-catastrophe type in earth-crossing orbits. Only a couple of hundred have been identified. Mount a thorough survey to find the rest of them, extrapolate their orbits for a few centuries in a computer, and see if one of them ever comes to occupy the same point in time and space as the earth.

If none of them is going to, that's good. And if one of them is indeed on a collision course, that's not too bad, either. Once the risk moves from the statistical to the actual, things can be done about it, especially as the survey would typically give its warning decades or centuries in advance. A nuclear explosion off to one side of the incoming rock could nudge it into an orbit that missed the earth. The technology to fly spacecraft to asteroids exists, as do the bombs. Putting them together into a successful mission over a period of years would be a tricky problem, but far less tricky than, say, waging the Gulf War.

The Spaceguard survey that Morrison and his committee suggested as a way of finding almost all the asteroids was not a huge affair. It required six specially designed telescopes of modest size operating for three decades and a data system to handle what they saw. Its costs were estimated at about $10m a year - a tenth of the price-tag for the air-safety programmes proposed two weeks ago and half a percent of Nasa's budget for space science next year.

But Nasa's big bucks, like those of its equivalents elsewhere, are fiercely fought over. They are spent on what the agencies' bosses and their beneficiaries ask for. And no-one is asking for asteroid surveys except the people already doing them, who were well represented on Morrison's committee. The focus of modern astronomy is not on the objects nearest to the earth but on those furthest away: vast black holes at equally vast distances, infant galaxies half as old as time and the fading embers of the Big Bang itself. There is, admittedly, a very small space mission heading off to a nearby asteroid at the moment, but that probably owes more to pressure brought to bear by the senior senator for Maryland, where it was built, than to a widespread scientific constituency.

When the Spaceguard report was released, Morrison pointed out to the press that there were about as many people involved in full-time searches for dangerous asteroids as there were employed in a typical McDonalds. Since then, one new asteroid surveillance system has been started in the US, largely thanks to the interest of the military, some of whom see protection against asteroids as a reasonable mission, or an excuse to try out neat weapons technology, or both. Other American searches, though, have closed down, as has the Australian programme, the only search that covered the southern skies. According to Duncan Steel, who used to work on the Australian search, there are now only about half a dozen people employed to track earth-crossing asteroids.

In short, nothing much is being done about the end of the world because it is a minority interest among scientists and no-one else feels particularly affected. For all that, asteroids are an otherworldly risk. They nicely highlight the worldiness of the relationship between science and policy. A theoretical danger can only be built into a policy-inducing risk with the help of a group of people who care about it, a constituency with a particular stake in the problem. Science simply doesn't matter much in policy debates unless there are interest groups to make use of it, lobbies with more clout than a burger-bar's worth of astronomers.

Then there's the problem of science going back on itself. People used to fear the skies, worry about Jove's thunderbolt and tremble at the sight of comets. Then the scientists took it on themselves to set the peasants right. The heavens were revealed as well-ordered clockwork, the history of the earth and life as one of slow gradual change rather than catastrophic fits and starts. By the middle of the 19th century, French astronomer Francois Arago was able to speak with pride of the fact that science had stopped people from worrying about comets, and that, as long as scaremongering journalists were assiduously slapped down, the sorry age of celestial superstition was gone for good. Science made the world seem sensible and its catastrophic demise silly. When science then comes back and says that the end of the world is, after all, a real possibility, it is not surprising that people laugh.

Sometimes, though, it's hard not to think that there is a deeper reason for "impact denial". Perhaps people do not want to see themselves connected to the universe in this sort of way. The geologists who for years resisted the impact explanation for the dinosaurs' death simply didn't want asteroids to play as big a role in the history of the earth as, say, the wanderings of one of its own tectonic plates. Tough - they do. Humans and the earth they live on are linked to the universe in all sorts of strange, indirect, unsettling ways. Worse yet, humanity now has the power to change these connections. We can empty seas and denude vast forests. We can warm an entire planet, and now, given just a little warning, we can push aside flying mountains. It's genuinely frightening to contemplate such power, especially when you realise how poorly decisions about using it are made or not made. Better to deny the risk of asteroid impact than to accept the fact the humans can redirect the stars in their courses. It's a delusion - a dangerous one, in this case - but you can understand it.

Start your day with The Independent, sign up for daily news emails
Have you tried new the Independent Digital Edition apps?
ebooks
ebooksAn introduction to the ground rules of British democracy
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Technical Author / Multimedia Writer

Negotiable: Recruitment Genius: This recognized leader in providing software s...

Recruitment Genius: Clinical Lead / RGN

£40000 - £42000 per annum: Recruitment Genius: This is an exciting opportunity...

Recruitment Genius: IT Sales Consultant

£35000 - £40000 per annum: Recruitment Genius: This IT support company has a n...

Recruitment Genius: Works Engineer

Negotiable: Recruitment Genius: A works engineer is required in a progressive ...

Day In a Page

Isis profits from destruction of antiquities by selling relics to dealers - and then blowing up the buildings they come from to conceal the evidence of looting

How Isis profits from destruction of antiquities

Robert Fisk on the terrorist group's manipulation of the market to increase the price of artefacts
Labour leadership: Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea

'If we lose touch we’ll end up with two decades of the Tories'

In an exclusive interview, Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea
Tunisia fears its Arab Spring could be reversed as the new regime becomes as intolerant of dissent as its predecessor

The Arab Spring reversed

Tunisian protesters fear that a new law will whitewash corrupt businessmen and officials, but they are finding that the new regime is becoming as intolerant of dissent as its predecessor
King Arthur: Legendary figure was real and lived most of his life in Strathclyde, academic claims

Academic claims King Arthur was real - and reveals where he lived

Dr Andrew Breeze says the legendary figure did exist – but was a general, not a king
Who is Oliver Bonas and how has he captured middle-class hearts?

Who is Oliver Bonas?

It's the first high-street store to pay its staff the living wage, and it saw out the recession in style
Earth has 'lost more than half its trees' since humans first started cutting them down

Axe-wielding Man fells half the world’s trees – leaving us just 422 each

However, the number of trees may be eight times higher than previously thought
60 years of Scalextric: Model cars are now stuffed with as much tech as real ones

60 years of Scalextric

Model cars are now stuffed with as much tech as real ones
Theme parks continue to draw in thrill-seekers despite the risks - so why are we so addicted?

Why are we addicted to theme parks?

Now that Banksy has unveiled his own dystopian version, Christopher Beanland considers the ups and downs of our endless quest for amusement
Tourism in Iran: The country will soon be opening up again after years of isolation

Iran is opening up again to tourists

After years of isolation, Iran is reopening its embassies abroad. Soon, there'll be the chance for the adventurous to holiday there
10 best PS4 games

10 best PS4 games

Can’t wait for the new round of blockbusters due out this autumn? We played through last year’s offering
Transfer window: Ten things we learnt

Ten things we learnt from the transfer window

Record-breaking spending shows FFP restraint no longer applies
Migrant crisis: UN official Philippe Douste-Blazy reveals the harrowing sights he encountered among refugees arriving on Lampedusa

‘Can we really just turn away?’

Dead bodies, men drowning, women miscarrying – a senior UN figure on the horrors he has witnessed among migrants arriving on Lampedusa, and urges politicians not to underestimate our caring nature
Nine of Syria and Iraq's 10 world heritage sites are in danger as Isis ravages centuries of history

Nine of Syria and Iraq's 10 world heritage sites are in danger...

... and not just because of Isis vandalism
Girl on a Plane: An exclusive extract of the novelisation inspired by the 1970 Palestinian fighters hijack

Girl on a Plane

An exclusive extract of the novelisation inspired by the 1970 Palestinian fighters hijack
Why Frederick Forsyth's spying days could spell disaster for today's journalists

Why Frederick Forsyth's spying days could spell disaster for today's journalists

The author of 'The Day of the Jackal' has revealed he spied for MI6 while a foreign correspondent