Long valued for its ornamental, monetary, and even scientific applications, gold has attracted speculators and miners throughout human history. The greatest quantities of gold mined today occur in ore—rock containing trace amounts of valuable materials. Obtaining even small quantities of gold usually requires extracting huge quantities of ore from open-pit or underground mines.
One of the largest open-pit mines is the “Super Pit” Mine near the city of Kalgoorlie in Western Australia. On February 15, 2010, the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this true-colour image of Super Pit and part of the neighbouring town of Kalgoorlie. The pit that gives the mine its name appears in the centre of the image, and some of the steep pit’s walls appear in shadow while others are illuminated by the Sun.
Related mining operations form a rough semicircle on the eastern side of the pit; a cluster of buildings east-northeast of the pit is Fimiston Mill, where ore is processed. Waste dumps and grey-white tailings ponds sprawl over the arid landscape. Tailings are the rocks and chemicals left over after the gold is extracted. Because the chemicals used to separate gold from rock are often caustic, tailings usually pose hazards to human and/or environmental health and must be treated carefully.
The metropolitan area of Kalgoorlie, marked by street grids and manicured green spaces, extends almost to the mine’s central pit. An airport, marked by a long runway, appears along the city’s southern margin. Founded during a late-nineteenth-century gold rush, Kalgoorlie, like the neighbouring mine, occurs near an area nicknamed the “Golden Mile,” which is considered especially rich in gold deposits.
As the beige and reddish colours in the image indicate, vegetation in the area is sparse. Like much of Western Australia, the area around Kalgoorlie and Super Pit is semi-arid, with hot summers and cool winters. January (summer) temperatures in Kalgoorlie frequently reach 40 degrees Celsius (over 100 degrees Fahrenheit).
NASA Earth Observatory image created by Jesse Allen, using EO-1 ALI data provided courtesy of the NASA EO-1 team. Text adapted from information issued by Michon Scott.