Scientists have been searching for the origin of some of the most precious metals on Earth - including gold, silver, and platinum - for almost six decades. And now we might finally have the answer. Heavy, and often valuable elements like these are called r-process elements, and they require an incredible amount of energy to produce. So far, no one's been able to explain how they came to exist in the Universe. But the discovery that an ancient dwarf galaxy called Reticulum II - about 98,000 light-years from Earth - has stars that contain a "whopping" amount of these metals...