We live in a universe of water. It is everywhere on Earth, throughout the solar system, and has been detected in the far reaches of space. While there are critical concerns for fresh water availability on Earth, water in all its forms (liquid, ice, and vapor) is ubiquitous in the cosmos. And where there’s water, there can be life.
There are nine “oceans” in the solar system; however, Earth is the only planet with liquid water on its surface. The other oceans are found under thick covers of surface ice. If both liquid and frozen water are counted, Earth ranks fifth in volume of its oceans. Most of the solar system’s oceans are on the satellites (moons) of planets, although some research suggests that Jupiter and Saturn may have the largest oceans.
Our world ocean contains 321 million cubic miles of salt water. A huge volume considering that all 7 billion people on Earth could fit into just one cubic mile. Remarkably, fresh water accounts for a tiny 3.5 percent of all our planet’s water. Of that amount, only 1 percent is available to humankind. The rest is locked in landbound ice, primarily in the Antarctic and Greenland.