Asteroids, also known as planetoids, are minor planets which are revolving around the sun. They are very small and millions in numbers in different sizes. The size range of asteroids is from feet to miles. Several asteroids have hit the earth in past. These asteroids are leftovers from formation of our solar system. Asteroids may be as large as Ceres which 950 kilometers. All the asteroids are irregulars in shape. They revolve round the sun is in elliptical orbits. Generally they are solid bodies which are made up of rock, metals (like iron) and other elements. Some asteroids contain water also.
An iron meteorite contains 91 percent iron, 8.5 percent nickel and also has cobalt. However a stony meteorite contains oxygen, silicon, magnesium, calcium and many more elements. The extension of these elements from the asteroid is called asteroid mining
The feasibility of asteroid mining is being prepared by Keck Institute for Space Studies (KISS) at Calfornia U.S. The study says that valuable elements from asteroid may be ruined and brought to earth to build solar-power satellites and water processed from ice to refuel orbiting propelling depots which is a cache of propellant that is placed in orbit around the earth. It is also estimated that gold, iridium, silver, platinum, titanium and many more elements can be obtained by asteroid mining. It will be a great impact as the key elements needed for modern industry could be exhausted in near future.