The Formation of the Oceans

You have come a long way - 13.7 billion years, in fact (give or take a few million)! According to scientists' theory, our journey began by witnessing an event called the Big Bang, during which all the matter emerged that formed the universe.

After the Big Bang, you traveled ahead nine billion years to a remote arm of the Milky Way Galaxy. Here, you watched a spiraling cloud of superheated hydrogen gas and dust slowly combine into our Sun and planets. One of these planets is called Earth, although at the time it was nothing more than a molten, rocky mass orbiting the Sun.

Taking a closer look, you saw on this molten rocky mass, countless low points called basins. As the Earth cooled, these basins filled with water to become a great ocean covering 71% of the planet. The balanced, beautiful, blue ocean you know today was not always balanced or blue. However, over the next several billion years, the ocean's chemistry reached a balance suitable for life as the inputs of elements from collected rainwater equaled the outputs from processes like evaporation.