Where You Can Live Each Day More Frightened than the Day Before

Thursday, June 21, 2007

Losing the Moon and the Sun and the Stars...

The Earth is moving very very slowly away from the Sun. This happens for two reasons. The first is that the Sun is constantly losing mass because of the solar wind. As the mass of the Sun decreases its pull on the Earth decreases and so the Earth moves slightly further away. The second reason is to do with tidal forces. In exactly the same way that the Moon is slowly moving away from the Earth, the Earth is very slowly moving away from the Sun. In the Earth-Moon case the Moon pulls on the Earth creating tides and slowing the Earth’s rotation very slightly, making the day longer. This action has a reaction - the Moons orbit is speeded up. If something travels faster it must move outwards to remain in an orbit and so the Moon slowly drifts away from us at a rate of 3.8 centimetres per year. The same situation happens with the Sun but the Earth’s influence on the Sun is much smaller than the Moon’s influence on the Earth. The result is the Earth’s tiny tiny drift away from the Sun

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