Even a small asteroid could destroy human race in near future – scientists

An international group of astronauts, scientists and others have called for a rapid expansion of efforts to detect asteroids capable of causing widespread destruction on earth, warning that this is one of the biggest threats to humanity in the coming centuries.

Led by Lord Rees, Britain’s royal astronomer, and Brian May, a PhD in astrophysics as well as guitarist with the rock band Queen, the group said a hundredfold increase in the number of objects detected each year was necessary over the next decade.

Academic projects to detect and track asteroids that might one day collide with earth have been under way for more than 50 years. The work was boosted in 1998 when Nasa was given a decade to identify near-earth objects with a diameter of more than 1km — a size that would turn a collision into a potentially extinction-level event.

However, astrophysicists warn that asteroids and meteors as small as 50m across could still cause devastation on earth, with a direct hit capable of wiping out a city and killing millions. An undetected meteor estimated to be 20m in diameter entered the atmosphere over Russia last year and exploded at a height of several miles, causing a shockwave that injured 1,500 people (pictured). Even the devastating 1908 impact at Tunguska in Siberia, the largest in human recorded history, was caused by an object of only around 50m, said Lord Rees.

Only around 1 per cent of the 1m asteroids, meteors and comets that could cause massive damage on earth have been detected so far, according to a declaration by the group issued on Wednesday.

“Nasa has done a very good job of finding the very largest objects, the ones that would destroy the human race,” said Ed Lu, an astronaut who flew three trips to the International Space Station. “It’s the ones that would destroy a city or hit the economy for a couple of hundred years that are the problem.”

“The more we learn about asteroid impacts, the clearer it becomes that the human race has been living on borrowed time” – Brian May, astrophysicist and Queen guitarist

“The more we learn about asteroid impacts, the clearer it becomes that the human race has been living on borrowed time,” said Mr May, who broke off his academic studies to become a musician but returned to complete his PhD at the University of London’s Imperial College in 2007. The campaign launched this week is intended to raise awareness and put pressure on governments to act, he added.

The group called for work in the near term to focus on detection rather than rushing to find ways to destroy or deflect dangerous objects. Dealing with an asteroid that is on a collision course with earth “is the easy part”, said Mr Lu. Since there would probably be decades to prepare for a future asteroid strike once it has been identified, “all you need to do when you have that much notice is run a spacecraft into them,” he said.

To complement Nasa’s ground-based telescopes, detecting the mass of small objects that could cause destruction on earth would require an infrared telescope mounted on a spacecraft orbiting between Earth and Venus, Lord Rees said.

The more than 100 signatories have joined the call for governments and private bodies to accelerate asteroid tracking greatly, including 34 US and Russian astronauts, and scientists such as the evolutionary biologist Richard Dawkins. The call also has the support of technologists such as Google’s Alan Eustace, who in October made a record parachute jump from the edge of space, and Nathan Myhrvold, a former chief technologist at Microsoft. – FT.COM