WHY 'THE EARTH' WET? earth mysteries of the earth

1. WHY 'THE EARTH' WET?

When the first Earth Day was held in 1970, geologists were still putting the finishing touches of plate tectonics, the model that explains how the Earth's surface takes shape. More than 40 years later, many puzzles remain unresolved when it comes to our planet. For example, dozens of spacecraft have mapped the surface of Mars with more precision the ocean depths of the Earth. We explore the boundaries of the Solar System, they send men to the moon, asteroids are thought to capture, but our planet, in many ways, is still a treasure trove of secrets.