Gold came from space!

Gold is great for many different reasons. It's pretty, malleable, and great for electronic circuitry. Dwarves love to sing songs about it, pirates love to bury it, and evil dark lords like to make rings out of it. But according to geologists at the University of Bristol, it came from space!

Approximately 4.5 billion years ago, the Earth was a roiling ball of magma. As it cooled, denser materials with greater mass would've sunk deep into the core, creating a core mostly comprised of iron, and leaving the outer layers bereft of any of the precious metals.

And yet, we've been mining these metals for thousands of years; metals that shouldn't have been there in the sort of quantity that we've found. So where did all these precious metals come from?

Scientists Matthias Willbold and Tim Elliott, after studying samples in Greenland, believe that the metals are a result of a 200-million-year long meteor shower, that impacted about 3.9 billion years ago. These meteorites had large quantities of these metals, which were slowly stirred into the Earths mantle by big currents in the molten composition of the ancient Earth, leading to the ore deposits we find today.

The ancient rock samples contained a slightly higher ratio of the tungsten isotope 182W, an isotope produced only in the first 50 million years of the solar system, signifying that the meteor shower had altered the composition of Earth's surface.

"Our work shows that most of the precious metals on which our economies and many key industrial processes are based have been added to our planet by lucky coincidence when the Earth was hit by about 20 billion tons of asteroidal material," said Willbold.

via ibtimes, via Nature