'Living On Borrowed Time': Scientists Warn Of Killer Asteroids

The world's leading experts in astrophysics launched a campaign this week to raise awareness and put pressure on governments to act on the terrifying possibility that killer asteroids could strike Earth and cause massive and widespread destruction.

The experts came together and issued a declaration on Wednesday calling for a rapid expansion of efforts to detect asteroids capable of destroying cities and killing millions, warning that this is one of the biggest threats humanity faces in the coming centuries.

Led by Lord Rees, Britain's royal astronomer, and Brian May, a PhD in astrophysics who is well known as a member of the rock band Queen, the group said the number of objects detected in space not far from Earth has increased a "hundredfold, " thus magnifying the danger facing mankind.

"The more we learn about asteroid impacts, the clearer it becomes that the human race has been living on borrowed time," said May.

Ed Lu, an astronaut who flew three trips to the International Space Station, said their group's main concern is not finding large objects zipping through space near Earth since that is the job of NASA which, he said, is doing its job well. But what concerns them more, Lu said, are the smaller rocks that could crash into Earth undetected. "It's the ones that would destroy a city or hit the economy for a couple of hundred years that are the problem," he said.

Space experts said rocks as small as 164 feet across would cause massive devastation on Earth if they penetrate through the atmosphere and crash either on land or sea.

Last year, an undetected meteor estimated to be around 65 feet in diameter punched through Earth's atmosphere and exploded over Russia, creating shockwave that injured 1,500 people.

In their declaration, the group pointed out that only around 1 percent of some one million asteroids, meteors and comets that could cause massive damage on Earth have been detected so far.

The group called for intensified effort to detect dangerous objects in space.

Dealing with an asteroid that is on a collision course with earth "is the easy part," said 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.

Lord Rees, for his part, said an infrared telescope mounted on a spacecraft orbiting between Earth and Venus should be launched to complement NASA's ground-based telescopes.

The declaration was signed on Wednesday by more than 100 astrophysicists, including 34 U.S. and Russian astronauts, and scientists such as the evolutionary biologist Richard Dawkins.

They called on governments and private bodies to accelerate asteroid tracking.

Efforts 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 one kilometer — the size of space rock that could trigger the extinction of the human race once it hits Earth.

NASA has devised a new map which shows the frequency of small asteroid impacts from 1994 to 2013 and it has provided clues on larger ones that could pose a danger to Earth. NASA's Near Earth Object (NEO) Program reveals that small asteroids frequently enter and disintegrate in the Earth's atmosphere with random distribution around the globe.