Only about 29% of the Earth is above sea level, so perhaps it should be called 'Water' or 'Ocean'?
Earth is often called the Blue Planet because the Atlantic, Pacific, Indian, Arctic and Southern oceans cover 71 percent of it.
The Pacific alone covers more than half the planet, and more than all the land areas combined.
For most of human history, almost nothing was known about the deep oceans.
The science of the oceans - Oceanography - is still full of chances to discover new things.
The deeper you go, the darker it gets, and most of the deep ocean never sees any sunlight.
Our knowledge of Earth and its oceans has been pieced together through the work of many individuals.
Every research cruise holds the potential for a surprising discovery.
Emily Klein, a marine geochemist at Duke University, studies volcanic eruptions, and the creation of new crust on the ocean floor.
To understand these eruptions, she focuses on processes that take place beneath the ocean floor, such as where the magma comes from, and how it moves through the crust.