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| "Ahh, home! This is the planet you live on. It has everything: Life, water, air, wind, all kinds of stuff! And it's a nice temperature all the time. Looks great too! I'd choose blue over the dead grey of a Saturnian moon."
Earth is the only known planet in the solar system that supports life. Adequate supply of water and oxygen encouraged the growth of organism on this blue planet. From space, Earth is often identified by its distinct dark blue oceans, its brown and green landmasses and its snow white clouds. Earth is the third planet from the Sun and lies at distance of 149,600,000 kilometers away from it (1 Astronomical Unit) and is ranked as the fifth largest planet in the Solar System with an average diameter of 12,756.3 km and a mass of 5.98 x 10^24 kg. The earth and its satellite, the moon, also move together in an elliptical orbit about the sun. The eccentricity of the orbit is slight, so that the orbit is virtually a circle. The approximate length of the earth's orbit is 938,900,000 km (583,400,000 mi), and the earth travels along it at a velocity of about 106,000 km/hr (about 66,000 mph). Earth takes about 23 hours 56 minutes 4.1 seconds to complete a single rotation on its own axis and approximately 365.26 earthdays to finish its revolution around the sun. As the period of the earthıs revolution isnıt accurate in complete days, therefore we had a leap year every four years to count in the extra day. |
