Which is the only planet not named after Greek or Roman deity?« Back to Questions List

Earth, is the only planet in the solar system that is not named after a Greek or Roman deity.   The Earth is the largest of the terrestrial planets and the fifth largest among all. It is the third planet from the sun after Mercury and Venus.   

Estimated age of the Earth is 4.54 billion years. So far among all planets, the Earth is the only planet known to have capability to support life. Life in the planet is believed to have arisen 4.1 billion years back.  The Earth that lies at a distance of 149,597,900 km from the Sun has an equatorial diameter of 12,756 km and polar diameter of 12,714 km. Thus, the shape of the planet is not an exact sphere. It is bulged at the center and flattened at the poles and this irregularity has made scientists describe the planet as geoid. 

It rotates around the Sun at a speed of 107,220 km per hour. It completes one rotation on its axis in 23 hours, 56 minutes and 4.091 seconds and makes one revolution around the Sun in 365 days, 5 hours, 48 minutes and 45.51 seconds.  As it rotates around the sun, one side faces Sun and receives direct sunlight and heat and that is the day. The other side does not receive sunlight and hence is a night for that side. As it rotates on its axis, the position changes gradually. The axis of rotation has a slight tilt of 23.4 degree from the vertical. This tilt and revolution of the planet causes season changes also.    The Moon is the only natural satellite of the planet and it is as big as the planet itself.  

Manly, the Earth has four layers named the inner core, the outer core, the mantle and the crust. The inner core has a temperature of 4,000 degree Celsius and consists of iron and nickel. The outer core has iron and nickel in molten state. The mantle has solid silicate material of iron and magnesium. The crust mainly is silicate rock called lithosphere. It is a rocky planet with a solid and dynamic surface that has mountains, canyons, plains, deserts and more. The earth’s atmosphere contains a mixture of many gases like nitrogen, oxygen, carbon dioxide, ozone, helium etc. About a fifth of the atmosphere is made up of oxygen, produced by plants. The atmosphere performs a number of duties to make the earth habitable. It filters out deadly rays from the Sun, traps enough heat to maintain the warmth of the Earth and prevents extreme cold and prevents meteorites from entering the earth surface.     

70% of the surface of the Earth is covered by water and hence it is a hydrosphere. It is the only known planet having water in liquid form and hence is also known as watery planet. The distance between the Sun and the earth keeps the water in liquid form. As the Earth looks like a cloudy blue colored sphere from the Earth, it is also known as blue planet. 
 

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