The history of Sudbury, Ontario, began -- literally -- with a bang.

The site that is now a Canadian mining town of about 162,000 people was formed some 1.85 billion years ago when an asteroid 6 to 12 miles in diameter slammed into Earth. The space rock rolled through the area and cracked our planet's crust, producing a mother lode of nickel, copper and platinum.

"The moment of impact was so great that it carved out an area 20 kilometers (12.4 miles) deep," according to David Pearson, a geologist at Laurentian University in Sudbury.

The cosmic object’s impact was not only geological but economical as well.

Today mining is a $3 billion-a-year business for Sudbury, where the first miners set up shop more than 100 years ago. The kidney-shaped basin where the asteroid hit is one of the world’s largest deposits of nickel, measuring about 40 miles long by 16 miles (65 kilometers long by 25 kilometers) wide.

The riches remained undiscovered until 1883, when workers building the Canadian Pacific Railway stumbled upon the basin. That set off a stampede of people interested in prospecting the precious metals.

In 1891, the Canadian Copper Company was formed to mine metal, mostly copper, from the basin. The company later became the International Nickel Company (INCO) after it was discovered that the ore from the basin, which was sent to refineries in the United States and Wales, actually contained a more valuable metal -- nickel.

According to the Nickel Development Institute, more than 2 billion pounds (900 million kilograms) of nickel are consumed worldwide – and demand keeps growing.

Today, INCO mines about 10 percent of the world market’s nickel from the Sudbury basin.

Evidence of the metal from this area mined by INCO is far-reaching. In 1938, some of Sudbury's nickel was used to help construct the Statue of Liberty. Some was used to build a roof for the National Cathedral in Washington, D.C.

Although most scientists today agree that an asteroid is responsible for the Sudbury basin, it was a hot issue in the scientific community up until 37 years ago.

"The fact that the asteroid left an oval shape, instead of its signature round one, made some scientists think it was caused by a volcanic eruption," said Robin Riddihough of the Geological Survey of Canada.

But in 1963, Riddihough said, findings by U.S. geologist Robert Dietz changed that theory.

At the time, Dietz was working with NASA to try to re-create the surface of the moon for Apollo astronauts to use for their training. While surveying Sudbury, Dietz identified cone-shaped rock fractures that could only be caused by high-intensity shock waves from something like an asteroid.

Since that discovery, scientists developed computerized models of the Sudbury basin analyzing the power of asteroid impacts. The results backed up Dietz’s findings and ruled out any theories describing the origins of the basin as volcanic.

Though the fruits of the asteroid have been beneficial to Sudbury, pollution from the mining industry over the past century ate away the area’s vegetation, killing off wildlife and making the denuded landscape look like the lunar surface.

By the 1970s, the town had the reputation as the biggest producer of acid rain-causing chemicals in North America.

The process: Metal mined from the basin contains sulfur. When the metal is purified, oxygen combines with the sulfur, producing sulfur dioxide. This acidic gas is then dispersed into the air and captured in clouds. When it rains, the compound is dissolved into raindrops. Over time, this tainted precipitation kills plants and pollutes lakes.

Faced with this situation, the government, academics and industry stepped up efforts to clean up the area.

"The results are phenomenal," said Darryl Lake, who played a key role in Sudbury’s makeover while chairing an environmental program at Sudbury’s Cambrian College.

Because of Lake’s program, which was funded by the Canadian government, steps were taken to neutralize the area’s highly-contaminated acidic soil by adding lime to it. The operation was successful.

"We just planted our millionth tree last year," Lake said.