1 GOLD IN SPACE The Mars Global Surveyor which functioned from 1996 to 2006 mapped Mars using a gold-plated telescope mirror The purpose of using gold on the telescope was not to show off or to waste money Rather the US National Aeronautics and Space Administration NASA uses gold for its reflective ability The Mars Global Surveyor used the telescope to chart the surface features of Mars The gold plating on the mirror captured infrared radiation that had bounced back from the planet’s surface Gold has special properties that make it ideal for a variety of unusual purposes It is one of the best materials for reflecting infrared radiation a type of invisible energy that is felt as heat Gold can also be applied in an extremely thin coating Many parts of space vehicles use a thin gold film By reflecting the infrared radiation the film helps control the temperature inside the spacecraft A thin layer of gold is also used on astronaut helmets to filter out the sun’s dangerous rays Closer to Earth many satellites are protected from solar heat by gold-coated films And this is only one of the unusual uses of gold in space and on our planet Without gold the Mars Global Surveyor could not have done its job 5
HIDDEN GOLD Gold has been valued for thousands of years as money and to make precious objects especially jewelry For jewelry gold is valued for its shiny rich color and the tradition that claims gold is valuable Gold’s properties as a metal are also beneficial in jewelry making It is easily worked and can be hammered into thin sheets drawn into narrow wires or cast into a variety of shapes In addition gold does not tarnish easily so it remains shiny and bright for a long time Many other metals are harder to work tarnish quickly or are dull with plain colors Golden Mirrors Space telescopes often use microscopically thin layers of gold NASA’s James Webb Space Telescope has 18 mirror segments that each received gold coatings approximately one-millionth of an inch thick These coatings are 200 times thinner than a human hair and yet the gold remains durable and reflective 1 This provides a light-gathering ability that helps scientists study the most distant objects in the universe The James Webb Space Telescope is scheduled to launch in 2018 Gold’s physical qualities are also ideal for many electronic uses Gold is so easy to work that it can be drawn into a wire a fraction of the thickness of a human hair It can be beaten into a sheet so thin it is translucent Therefore gold can be used for very fine even microscopic electronic parts Resistance to tarnish is extremely important for any metal used in electronics Many electronic devices use very low voltages and currents The flow of electricity can be easily interrupted if there is any corrosion or tarnish in the system Electronic components made with gold are highly reliable as they rarely corrode 6
Many electronic devices from cell phones to television sets contain small amounts of gold Mobile phones contain an average of 33 gold-plated contact points a type of switch to turn the electric current on or off This averages 0 001 ounces 0 034 g of gold per phone which is worth less than two dollars 2 Computers also use gold in many electronic parts The reliability and high conductivity of gold is ideal for quickly and accurately transmitting digital data between components GOLD’S VALUE IN SPACE For these same reasons gold is used in space vehicle electronics In fact NASA uses gold throughout its spacecraft Space travel can cost billions of dollars and once a vehicle is launched it is difficult or impossible to repair Therefore the most reliable materials must be used Because gold does not corrode any electronics found in spacecraft are likely to have gold components Spacecraft also use very thin films of gold between some moving parts Two sheets of gold will slide past each other easily so the gold acts as a 7 Mixing Metals Pure gold is too soft to stand up to rough use A ring made of pure gold would quickly be damaged through normal wear Therefore gold is often alloyed or combined with other metals such as silver copper or platinum Mixing gold with another metal makes it sturdier However alloys do not resist tarnish as well as pure gold Different alloys change the color of the product Gold may have tints of white pink peach green or black because of the alloy metals The Black Hills of South Dakota is known for this type of jewelry Black Hills gold jewelry often features flower or grapevine designs The grapes are made of yellow gold while the leaves are green and pink Gold is alloyed with silver to produce the green and with copper to produce the pink
