'Very few asteroids in solar system may be worthy of getting mined'

A new study has suggested that that few asteroids are going to be worth mining.

Harvard astrophysicist Dr Martin Elvis has argued that just about 10 near-Earth asteroids might be suitable for commercial-scale mining, the BBC reported.

Dr Elvis, from the Harvard-Smithsonian Center for Astrophysics in Cambridge, US, developed an equation to find out the number of asteroids in the Solar System, which could be exploited in a cost-effective way.

He worked out the factors that would make an asteroid commercially viable to mine, and what fraction of space rocks met these requirements.

Elvis assumed that mining operations would like focussing on iron-nickel asteroids (known as M-type), which are considered the most promising targets for finding so-called platinum-group metals, including platinum, along with iridium, palladium and others.

However, according to his analysis, just about one per cent of near-Earth asteroids are rich in these elements.

Suitable asteroids should be easy to reach, which narrowed down the pool by ruling out all but the near-earth objects.

The size of the asteroid was also a factor; as mining asteroids smaller than about 100m would be cost-efficient.

The research paper is set to be published in the journal Planetary and Space Science.