Published: 04 Sep 2017

Can the Earth be covered in gold?

Covering the entire planet in gold probably sounds like the aspirations of the ancient oligarchs who swam around in far too much wealth. However, we know that the precious metal is highly malleable and can be spread out into extremely thin sheets.

So, let us put our speculations aside for a while and quickly explore some real numbers to see if this is, in fact, possible.

To calculate this, we must answer the following questions:

1. How much Gold do we have on planet earth?

There are various theories that postulate where gold comes from and why it exists on planet earth. Some experts say that all the gold we have on planet Earth came from huge meteors from outer space back in the early days of our planet, while others say that gold has existed on earth and in its composition since the formation of our planet. However for the purpose of our exercise, it is not the origins of gold that are important to us, but instead how much gold do we physically have. According to an article in the Money Metal Exchange1, the total world gold mined 173,000 metric tons from 1493-2016. Of the 173,000 metric tons, 91% of it has been mined in the last 66 years.

2. What is the surface area of planet Earth?

Planet Earth is the 5th largest planet in the Milky Way and is less than 10% the size of Jupiter – the largest planet in our solar system. It has a radius of 6,371 km and has a total surface area of a whopping 510.1 Million Square Kilometers, according to NASA’s Earth Fact Sheet.

3. How thick a layer of gold could you cover planet earth in?

Using the above data and some (relatively) simple math – we can now try and figure out how thin gold would have to be pressed to cover the entirety of Earth in a gold film. This number, taking into consideration all the gold mined in the last 500 years, would be a mere 0.01757 nanometers thick – less than 1% the thickness of the average human hair. Unfortunately, the American Museum of Natural History found that gold can only be 180 nanometers thin.

So, we might have to wait a few more years until science develops a method to flatten gold even more.