Know The Planet Where We Live.
Earth is one of the planets in the solar system and one of the four made of rocks. Earth is unique because it is the only planet that supports life. The distance from the sun makes it neither hot nor too icy cold. It helps the existence of water here in liquid form. Earth has an oxygen-rich atmosphere. Oxygen and water are two key factors that allow life to flourish on Earth. From the analysis of meteorites, Geologists believe that the earth may be from the solid piece of an exploded planet. Meteorites are natural objects that fall to the earth from space. They are composed of iron or stone or a mixture of both. The two main types are chondrites and achondrites. Achondrites Meteorites . More than 70% of the earth's surface is water. Above sea level, the earth's land surface has seven land masses called continents. Earth is in a constant state of change above and below sea level. Most volcanoes and earthquakes are due to the movements of rocky plates in the earth's crus