Our Home "Earth"

Updated: Aug 21

The fifth-largest planet in the solar system and the third planet from the Sun, the Earth, is slightly more giant than Venus and is the most prominent planet among the four planets closest to Sun.

Earth is the only planet in our solar system to have a habitable environment and life.

The name Earth is a Germanic word that means 'the ground'.

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The formation of Earth took place about 4.5 billion years ago. It has four layers - the inner core, outer core, mantle, and crust.

The inner layer is composed of a solid sphere made of iron and nickel metals about 759 miles (1,221 kilometers) in radius and having a temperature of 5,400 degrees Celsius, surrounded by the outer layer of 1,400 miles (2,300 kilometers) thick, made of iron and nickel fluids.

Between the outer layer and crust, there is a mantle which is a hot, viscous mixture of molten rock about 1,800 miles (2,900 kilometers) thick and has the consistency of caramel.

The outermost surface of the Earth is known as the 'crust'. It is 19 miles (30 kilometers) deep on average on land. At the bottom of the ocean, the crust is thinner and extends about 3 miles (5 kilometers) from the seafloor to the top of the mantle.

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The radius of Earth is about 6,371 kilometers making it the fifth largest planet. And the average distance between the Earth and the Sun is 151.7 million kilometers, that is, 1 AU (astronomical unit).

Due to this, sunlight takes 8 minutes to reach the surface of the Earth.

The temperature of the Earth is hospitable, with a mix of chemicals that have made life abundant here. The surface is covered with liquid water. Since the temperature is favorable, it helps water to be in a liquid state. Earth's vast oceans provided a convenient place for life to begin about 3.8 billion years ago. And climate change is one of the most important factors for sustaining life on Earth.

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Earth takes 23.9 hours to complete one rotation and 365.25 days to complete one trip around the Sun. Our planet's axis is tilted by 23.4 degrees concerning the Earth's orbit around the Sun. Because of this tilt, Earth has different seasons.

The northern part is tilted towards the Sun for a period, and then the southern hemisphere is tilted towards the Sun for some time. Because of this Earth has its seasons.

Like different planets, Earth also has mountains, volcanoes, and valleys. Earth's lithosphere, which includes the crust (both continental and oceanic) and the upper mantle, is divided into massive plates constantly moving. Ocean on Earth covers almost 70 percent of its land area and has an average depth of 4 kilometers which contains 97% of Earth's water, and most of the volcanos are hidden under the oceans.

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The Earth's surface has an atmosphere consisting of 78% nitrogen, 21% oxygen, and 1% other gases such as argon, carbon dioxide, and neon. The atmosphere secures us from the harmful radiation that comes from the Sun. It protects us from meteoroids as most of them burn in the atmosphere while coming towards the surface. It also affects climate change in the long and short term.