杏吧原创

One of the UK鈥檚 foremost asteroid experts has accused the UK government of ignoring the threat of a meteorite impact.

After commissioning an expert report on the issue, the government announced plans this year for a public information centre, but Duncan Steel, from the University of Salford, says this is equivalent to 鈥渟ending journalists to the Olympics, but not sending an athletics team鈥�.

鈥淚t is a real and significant threat, on a par with dying on an airliner,鈥� he said. 鈥淏ut there has been no announcement of any budget for any research in this area 鈥� a few people in the UK like me are trying to do stuff in our spare time.鈥�

鈥淭he US are ploughing ahead and doing a wonderful job given the funding they have and Japan, Italy, Germany and France all have programmes,鈥� Steel says. 鈥淣o project could have a better cost-benefit ratio. But it鈥檚 a vote loser as no-one takes it seriously. People don鈥檛 know anyone who was killed by an asteroid.鈥�

On the trail

The latest analysis from the University of Pisa on potential Earth-approaching objects reveals 14 asteroids that cannot currently be ruled out. Objects are added to the list and deleted regularly, as continued observation refines knowledge of the trajectory.

For example, object 2001QQ₁₄₂, is about 1.25 kilometre in diameter and has dozens of potential impact dates between 2006 and 2079. However, the largest current probability of impact is just one in 10 million in 2006 and this is based on only five days of observations.

Objects over one kilometre would cause a 鈥済lobal catastrophe鈥�, with between a quarter and a half of the world鈥檚 population wiped out.

The problem, said Steel, is that only half of the objects over one kilometre are spotted and less that one percent of those a few hundred metres in size. Even a 50-metre object can cause enormous regional damage, like the 1908 Tunguska impact in Siberia. 鈥淚f we want to find these, we need to up the game,鈥� says Steel.

Small and faint

The current search program in US only use telescopes with apertures of one metre. These are US air force installations in New Mexico and Hawaii. 鈥淚n order to find the smaller, fainter ones in the sky we need bigger telescopes,鈥� he says.

Another problem is that no-one is searching for objects in the southern hemisphere. Steel did have a programme from 1990 to 1996 at the Anglo-Australian observatory that allowed objects picked up by the US to be tracked for longer.

Finally, if we are to do something about a future asteroid threat, we need to know our enemy much better, says Steel: 鈥淚f you don鈥檛 know what they are made of, we don鈥檛 know if we need an elephant gun or a butterfly net.鈥�

Detonating a nuclear bomb in front of an asteroid should vaporise the front of the asteroid enough to change its flight path without fragmenting it, but Steel says, 鈥渕aybe we should start practising now鈥�.