January 31, 2024 – Theme Week Day 3

We’re right in the middle of our theme week on 5 Things You Thought You Knew! What’s the only man-made single structure on Earth that can be seen from space orbit? It’s not the Great Wall of China! It’s the Bingham Canyon Mine in Utah.
The Great Wall of China can’t be seen with the naked eye from the moon. The width of it from the moon would be the same as a human hair viewed from 2 miles away. You’d need visual acuity 17,000 times better than the norm to see the Great Wall from the moon. A more controversial question is whether you can see it from low Earth orbit, which is an altitude of as little as 100 miles. NASA says that it’s barely visible, and only under nearly perfect conditions. According to astronauts Eugene Cerna and Ed Lu, the Great Wall is visible from low Earth orbit, but only under favorable conditions and if you know exactly where to look.
The Bingham Canyon Mine is an open-pit mining operation that extracts a huge copper deposit southwest of Salt Lake City. It’s the largest man-made excavation and the deepest open-pit mine in the world. Over 18 million tons of copper have been removed to date, more than any other mine in history. The pit is .75 miles deep, 2.5 miles wide, and covers 1,900 acres. To give you an idea of its depth, you could stack 2 Sears Towers on top of each other and it still wouldn’t reach the top of the mine.
Copper ore was first discovered in the area in 1848 by 2 brothers, Sanford and Thomas Bingham, who grazed their cattle there. The extraction of ore began in 1863, with the mine starting production in 1906.
Today, the copper market is booming due to its use in construction, telecommunications, and electronics. Bingham Canyon Mine is the 2nd largest copper producer in the U.S., operating 24 hours a day 365 days a year, and removing 400,000 tons of material from the mine every day. In 2002, the Salt Lake City Olympic Medals were made from gold, silver, and copper extracted from the mine. Learn more here.