Unsurprisingly, humans are fascinated with what lies deep below the surface of the earth. But ever since the first artificial satellite was sent into space in 1957, humans have also been infatuated with looking high up to discover the secrets of the stars. And now, with the help of global space agencies and private companies, we know more about the universe than ever before. But as we continue to stare skywards in wonder, are we overlooking another equally mysterious world back on Earth?