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Measuring the size of Earth – Mocomi.com

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Measuring the size of Earth – Mocomi.com

Learn how size of Earth is measured, the techniques used centuries back to the one's used now, with the help of our interactive media article, visit: http://mocomi.com/measuring-the-size-of-earth/

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Measuring the size of Earth – Mocomi.com

1. 1. Measuring the size of Earth It is next to impossible to measure the size of the Earth using a tape measure- it is just too big. We can measure the size of the Earth accurately with the help of mathematics. One way of doing it is to look at a star from two places on Earth. If the distance between these two places is known, we can get answers to how big the Earth really is. UNF FOR ME! Copyright 2012 Mocomi & Anibrain Digital Technologies Pvt. Ltd. All Rights Reserved.© Geography for Kids mocomi.com/learn/geography/
2. 2. Measuring thesize of Earth Satellites which are used for mapping is another way to measure the size of the Earth. These satellites keep a watch on Earth from 35,900 kilometers away in space. They can measure the angle between themselves and the two places on Earth. Once scientists know what these angles are, it is used to get a measure of the Earth's radius; the distance from the center of the Earth to its surface. The radius of the circle will help you determine its circumference. 35,900 kilometersi 17.4 R MEASURING THE EARTH FROM A SATELLITE UNF FOR ME! Copyright 2012 Mocomi & Anibrain Digital Technologies Pvt. Ltd. All Rights Reserved.©
3. 3. The Greek scholar Eratosthenes found the circumference of the Earth by studying the shadow made by a tower in Alexandria, Egypt. He measured the angle that the shadow made at noon on the longest day of the year. He knew that on the same day at the same time in Syene, the sun was at its highest point. It shone straight down into a well, so it must be directly overhead. HOW ANCIENT GREEKS MEASURED THE EARTH Measuring thesize of Earth UNF FOR ME! Copyright 2012 Mocomi & Anibrain Digital Technologies Pvt. Ltd. All Rights Reserved.©
4. 4. The angle Eratosthenes measured at Alexandria was 7.2 degrees, or a fiftieth of a circle. So, he multiplied the distance between Syene and Alexandria by 50 to get the size of the Earth. He found that it was about 40,000 kilometers around. Measuring thesize of Earth UNF FOR ME! Copyright 2012 Mocomi & Anibrain Digital Technologies Pvt. Ltd. All Rights Reserved.©
5. 5. INTERESTING FACTS Measuring thesize of Earth In the 6th century BC, Pythagoras claimed that the Earth is round because both the sun and moon were. It was Eratosthenes however in the 3rd century BC whose estimate came very near the 40,075 kilometers, now known to be the circumference of the planet at the equator. Today's sophisticated and advanced equipment shows that the Earth is 42 kilometers thicker at the equator than around the poles. 40,075 kilometers UNF FOR ME! Copyright 2012 Mocomi & Anibrain Digital Technologies Pvt. Ltd. All Rights Reserved.©
6. 6. PROJECT Measuring thesize of Earth The Greek scholar Eratosthenes was known for a few other discoveries. What are they? Eratosthenes made use of which other great scholars works while discovering the size of the Earth? UNF FOR ME! Copyright 2012 Mocomi & Anibrain Digital Technologies Pvt. Ltd. All Rights Reserved.© For more such interactive article and video, visit: mocomi.com/learn/