Planet Earth Facts

Planet Earth Facts
Earth, also known as the Blue Planet, is the only planet in the Solar System that supports life. The Earth is, thus, unique in more than just one way. Several theories surround how it came into being. So, let's unearth some interesting facts about our planet and find out what makes it so special.
Did you know?
According to the Snowball Earth hypothesis, the Earth's surface froze almost entirely, at least once around 650 million years ago.
The Earth was formed approximately 4.5 billion years ago. Since the ancient years, there have been many theories and myths regarding the shape of the Earth. From the time when it was believed to be the planet around which the Sun revolves, till today when it is on the brink of global climatic change, our planet has been constantly surprising us with its secrets.

With the help of science and advanced technology, it has been possible to bust myths and dig deep into stories associated with our planet.

Facts and Figures

The Earth is believed to have resulted from the collisions that took place in a vast cloud of gas. In due course of time, the gases, dust, and other particles combined to form solid masses called asteroids and planetesimals. On further collision and accretion, these objects formed the entire Solar System.

The shape of the Earth is an oblate spheroid, bulging at the equator and flattening at the poles. This bulge around the equator is caused by the Earth's rotation.

The Earth is the fifth largest planet in the entire solar system.

The distance of the Earth from the Sun is approximately 93,000,000 miles. This distance is considered as 1 Astronomical Unit (AU).

Did you know that ours is the only planet whose name has not been derived from Roman or Greek mythology? The name has originated from the 8th century Anglo-Saxon word erda. It means ground or soil.

Oceans cover around 70% of the Earth's surface.

The Earth takes approximately 23 hours, 56 minutes, and 4.091 seconds to rotate around its axis. Therefore, on an average, it takes around 24 hours to complete a full rotation.

The Earth has four layers: the crust, mantle, inner core, and the outer core. While the crust and inner core are known to be in solid state, the outer core and mantle are in semi-fluid state. The crust and upper mantle together form the lithosphere. Beneath the lithosphere lies the highly ductile asthenosphere, which is known to change with change in temperature.

The atmosphere is divided into five principal layers: the troposphere, stratosphere, mesosphere, thermosphere, and the exosphere. The ozone layer, which shields us from the Sun's UV radiation, is located in the stratosphere, while the ionosphere, which plays a crucial role in radio communication, is a part of the thermosphere. As for the atmospheric composition of the Earth, it is made up of nitrogen (78 percent), oxygen (21 percent), and other trace gases.

The gravitational pull between the Earth and the moon is what causes the tides in the oceans and seas.

The speed at which the Earth travels through space is 66,700 miles per hour (mph), which comes to 18.5 miles per second (mps). As for the Earth's rotation, the speed is 1037.56 mph at the equator, and decreases as you move away towards the poles wherein it is very very slow―as good as zero. This difference in speed can be attributed to the difference in the Earth's circumference.

Explorer 6 first photographed our planet from space in the year 1959. Yuri Gagarin was the first human to be able to view Earth from space in the year 1961.

The Earth is one such planet that provides an atmosphere, which helps to sustain life. It has the requisite quantity of water and other suitable conditions that are very essential for any form of life to exist.

Our planet is only slightly larger than Venus. However, Venus's mass is only around 80% of Earth's. This is because of the dense nickel core present in the center of the Earth.

The four seasons that we experience are a result of the Earth's rotation on its tilted axis. Currently, the planet is tilted at an angle of roughly about 23.4°.

Did you know that the field of gravity is not the same in all areas over the surface of the Earth? This is probably why you feel slightly heavier in certain areas.

The deserts on Earth are not entirely composed of fine sand. About 80% of them consist of rocks of varying sizes from pebble to gravels.

The total surface area of the Earth is approximately 200 million square miles.

Apart from one natural satellite, that is the Moon, Earth also has 2 quasi-satellites in the form of asteroids, 3753 Cruithne and 2002 AA29. While the orbit of 3753 Cruithne is synchronized with that of the Earth, 2002 AA29 has its own independent path around the Sun.

As opposed to 3753 Cruithne, which has a diameter of 5 km, 2002 AA29 only measures 60 meters in width. It orbits the Earth in a shape similar to that of a horseshoe, as a result of which it comes close to our home planet every 95 years.

The Earth was a supercontinent about 200 million years ago before breaking down into its current form.

Mountains, volcanoes, and earthquakes are a result of Earth's tectonic activity. So far, the Earth has been the only planet to boast of active plate tectonics.

99% of the Earth's glaciers are in the Arctic and Antarctic region. These store 70-80% of the planet's freshwater.

While the Earth's continental crust is largely made up of granite, the oceanic crust is made up of basalt. At 2.6 g/cm3, the density of the continental crust is less than that of the oceanic crust (3.0 g/cm3), which explains why the continents are at higher elevation as compared to oceans.