Long after the Earth formed it was bombarded with leftovers from the formation of the solar system, the same materials that went into our planet in the first place. When the mantle material made its way to the surface again in our active geology, the gold came along. A rather smallish asteroid is responsible for the world's largest deposit of nickel. Located in Sudbury, Ontario, Canada, the impact site produces about 10 percent of the world market's supply of nickel. The asteroid, only 6 to 12 miles in diameter, slammed into the Earth about 1.85 billion years ago and plunged more than 12 miles into the ground.
Impact is the way of things in the solar system.
Impacts by large asteroids may have been primarily responsible for the several devastating mass extinctions in our planet's history, including the collision 65 million years ago the led to the extinction of the dinosaurs. With these thoughts of death and destruction from space in mind, it's ironic to think that Earth was also lavished with material that's so precious to us today. One day, then, the science fiction idea of mining asteroids may become a reality - instead of waiting for the asteroids and meteors to come to us, we'll just go to them. The Cosmos appears every Sunday in the Youngstown Vindicator .