There is much to be said about the planet humans live on. It is the third planet from a star named the Sun.
The Earth is shaped like a sphere and composed mostly of rock.
Over 70 percent of the Earth’s surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen.
Earth has a single large Moon that is about 14 of its diameter and, from the planet’s surface, is seen to have almost exactly the same angular size as the Sun. With its abundance of liquid water, Earth supports a large variety of life forms.
Planet Earth is more than 4.5 billion years old, just a shade younger than the Sun. Recent evidence actually shows that planet Earth was formed much earlier than previously believed, just 10 million years after the birth of the Sun, a stellar event typically put at 4.6 billion years ago. The Earth’s surface is relatively young by astrological standards.
Facts about the planet earth:
Start with some of the basic facts that describe the planet Earth. The circumference of our planet is 24,901.5 miles long, with a diameter of nearly 8,000 miles.
The surface area of planet Earth is 196,935,000 square miles, but only 30 percent of it is covered by land. The Earth’s oceans cover the other 70 percent. Of that, 97 percent of the total water is salt water, leaving only 3 percent as fresh water. The highest point on Earth is located on Mount Everest at 29,028 above sea level. The lowest point is in the Dead Sea at 1,302 below sea level.
Earth is the third planet from the Sun and the fifth largest. The crust varies considerably in thickness, it is thinner under the oceans, thicker under the continents.
The inner core and crust are solid; the outer core and mantle layers are plastic or semi-fluid. The various layers are separated by discontinuities, which are evident in seismic data.
The planet Earth is the densest major body in the solar system. Unlike the other terrestrial planets, planet Earth’s crust is divided into several separate solid plates, which float around independently on top of the hot mantle below. The theory that describes this is known as plate tectonics. It is characterized by two major processes spreading and subduction.
Spreading occurs when two plates move away from each other and new crust is created by upwelling magma from below. Subduction occurs, when two plates collide and the edge of one dive beneath the other and ends up being destroyed in the mantle. There is also transverse motion at some plate boundaries (i.e. the San Andreas Fault in California) and collisions between continental plates (i.e. IndiaEurasia). There are (at present) eight major plates.
In addition, 71 percent of the planet Earth’s surface is covered with water. Earth is the only planet on which water can exist in liquid form on the surface. Liquid water is essential for life as we know it. The heat capacity of the oceans is also very important in keeping the Earth’s temperature relatively stable.
Liquid water is also responsible for most of the erosion and weathering of the Earth’s continents, a process unique in the solar system today. Of the total amount of water present on Earth 97 percent is salt water leaving only a modest 3 percent as fresh water.
Earth is the only known planet to sustain life. Currently, the human population of the Earth is 6,530,000,000 (6.53 billion), spread out over 193 countries. The world population growth is 1.14 percent. This means at the current rate of growth, the earth’s population will double in 61.4 years.