Exploration Hub

The sun, space and precious metals: reflecting on a golden opportunity

February 26, 2020

Gold has been associated with the sun since the beginning of civilization. Whether it was the Incas in Peru, the Greeks, or Hindus in India, gold stood as an icon of the sun. And as the sun was a source of life, it represented purity and perfection. In fact, most of these civilizations portrayed the sun as a symbol of God. Take a moment to think of their reactions, centuries later, if they realised we were using this precious metal as our best protection from the sun itself? 

Did you know that gold is what keeps astronauts alive in space? Without the use of gold, astronauts would be ‘cooked’ by the sun’s strong radiation. Long science montage cut short, gold is crucial in acting as a heat shield. But more importantly, it acts as a radiation shield for our astronauts against the sun.


How it works

The sun transmits heat onto the Earth by mostly warming the atmosphere. We experience that heat via convection, kind of like a turkey in the oven.

In space, however, direct radiation transfers heat, like a dish being warmed in a microwave. So our biggest concern about keeping objects and astronauts cool in space is more about reflecting the radiation, than keeping the objects insulated. And it turns out that gold has reflective qualities that fit the bill. There are other metals that act as great reflectors, like silver, copper and aluminium, but none of them could tackle UV radiation, while also absorbing quite a lot of the visible light. Think of gold in this scenario like a superpowered version of your polarized sunglasses.

Gold is also pretty handy in space exploration, because it doesn’t rust as fast as other metals. That means it needs less maintenance, which is a massive plus especially when you are in outer space.

Not convinced yet? Here’s a list of the ways NASA uses gold in its operations:

  • Circuits - need a highly dependable conductor of electricity? You don’t need to look past gold.
  • Sample collectors - Gold tools are a great before/after shot for space missions. This is because particles in space imprint a lot easier on gold when they hit it
  • External coating - Gold coated film outside the spacecraft not only looks amazing, but also stabilizes the temperature inside it and reflects radiation back into space
  • Micro-electronics - Gold is more than an excellent conductor, it’s also resistant to corrosion.
  • Lubricant - The lubricant we usually use on machinery on Earth, actually gets broken down by the radiation in space. So we use gold instead, as a lubricant between parts of satellites and spacecrafts. 

While we could easily use a bunch of different metals to do each of these functions separately, gold is a one-size-fits-all solution, with its impressive reflective, resilience and conductivity properties. So next time you hear people talking about gold as just jewelry, or as a monetary investment, you might want to mention to them that gold helped us get to the moon.