Recent scientific discoveries have unearthed a vast ocean of water hidden beneath the Earth's surface, stored in a sponge-like state within a mineral called ringwoodite. This hidden reservoir, located 400 miles underground, could potentially hold three times more water than all the oceans combined. The discovery, based on studying earthquake shockwaves and the composition of mantle rock, suggests a global water cycle that extends far beyond the Earth's surface. This new understanding of Earth's water cycle adds to other remarkable scientific discoveries, such as the identification of a previously unknown ecosystem thriving within volcanic crust, highlighting the vast and ever-evolving secrets of our planet.