Earth

Earth is the only known planet in the universe where the life exists. Along with Mercury, Venus and Mars it belongs to the group of so-called rocky planets that are relatively small in size, have solid surface, and usually the atmosphere too. Of all the rocky planets, Earth has the highest density and surface gravity, the strongest magnetic field, and the fastest rotation. Even now, it is also the only planet where it is possible to observe active plate tectonics, which constantly transforms the Earth's surface.



A suitable distance from the Sun along with the hot core ensure that it is the only planet of the solar system that has constantly liquid water. Water areas cover about 70% of the Earth's surface, the rest are the continents. Thanks to the liquid metal core the Earth has also strong magnetic field.



Orbit, the greenhouse effect, volcanic activity, gravity, magnetic field and oxygen-rich atmosphere are unique qualities that created Earth a water planet. The Moon also helps to stabilize the Earth's rotational axis, allowing the formation and evolution of living organisms.