Oceans cover more than 70% of the Earth’s surface, and scientists argue that the planet’s interior also contains a lot of water. But where did all this water come from?
One look at planet Earth on a map, or based on an image taken from space, ought to convey just how immense and important our oceans are. After all, they cover 72% of the planet’s surface, occupy a total volume of around 1.35 billion cubic kilometers (320 million cu mi), and are essential to life as we know it. And in their great depths, many mysteries still wait to be discovered.