NASA has called on amateur astronomers and other citizen-scientists to help identify the smaller and potentially destructive asteroids lurking in the cosmos, which could wipe out a city upon impact with Earth.
Scientists estimate that about 90 per cent of asteroids that are one kilometre or larger which pose potential planet-wide danger have been surveyed.
However, more than 99 per cent of asteroids that are 30 to 40 meters in size-which might not destroy the planet, but could very easily wipe out a city - have yet to be found and tracked, the 'National Geographic' reported.
The announcement coincides with the agency's plans for a new mission to capture an asteroid, redirect it to lunar orbit, and then send humans to study it, said Brian Muirhead, NASA's chief engineer and the leader of the Asteroid Redirect Mission study team.
"What we need to do is increase the frequency of identification of asteroids such that we can also track them and characterise them," said Muirhead.
"That will give us a choice (to see) which (asteroid) we want to grab hold of and bring back to the Earth-moon system," said Muirhead.
On the same day, an asteroid named 2012 DA14 brushed past Earth from a distance of less than 28,000 kilometres away.
The asteroid-nearly 30 meters in diameter, with the capacity to destroy a city-was so close that it threaded its way between the orbits of most telecommunications satellites.
"This was a wake-up call for the world on the threat near-Earth asteroids can pose for the human population," said Ed Lu, a former NASA astronaut and the chief executive of B612, a nonprofit foundation that has been working for years to raise awareness about asteroid threats.