All the Water on Planet Earth

Illustration Credit & Copyright: Jack Cook, Woods Hole Oceanographic Institution, Howard Perlman, USGS

Explanation: How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth’s surface, these oceans are shallow compared to the Earth’s radius. The above illustration shows what would happen is all of the water on or near the surface of the Earth were bunched up into a ball. The radius of this ball would be only about 700 kilometers, less than half the radius of the Earth’s Moon