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Speed of Earth: The circumference of the Earth at the equator is 25,000 miles. The Earth rotates in about 24 hours. Therefore, if you were to hang above the surface of the Earth at the equator without moving, you would see 25,000 miles pass by in 24 hours, at a speed of 25000/24 or just over 1000 miles per hour. The earth orbits around the Sun at a speed of 30 kilometers per second (67,122 MPH). The frame of reference here is a coordinate system centered on the Sun. The Sun orbits around the center of the Milky Way Galaxy at a speed that is about 200 kilometers per second. This is in a frame centered on the Galaxy and which does not rotate. Most of the stars near the Sun have similar motions. The Galaxy itself is moving at several hundred kilometers per second with respect to a reference frame defined by the cosmic microwave background (radiation left over from the Big Bang).
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