Daniel cain, age 10, of gary, ind.., for his question:

How marny different motions has the earth?     

We earthlings do not notice it, but our globe is moving at a fantastic speed. What's more, it is whirling through several different jigs at one and the same time. We feel motion when we are speeding up or slowing dawn. The earth's merry jogs go on at a fairly steady pace., which is why our solid old globe seem to be standing still.

The round earth spins around on its axis like a top. This motion is its rotation, and each rotation takes 24 hours minus four minutes. In a year, our busy Globe has to make a 600 million mile journey around the sun. This is its revolution. The earth and everything on it revolves around its orbit at an average speed of 18.5 miles a second.     The entire solar system is also on the move. It is traveling a vast orbit Around the giant pinwheel of stars called the galaxy. The average speed of this Galactic revolution is 170 miles a second. The earth, with the rest of the solar of system, completes one~these staggering orbits in about 200 million years. The earth's axis also moves. The two poles do not remain pointing to the same Fixed spots in the heavens. They wander around in wobbly circles about 40 feet wide The north pole also wanders around in wobbling motion called precession. Each one of these wandering circles takes 26,000 years.  The motion of precession is s somewhat like the wobble of a spinning top that is beginning to slow down. As the north pole swings around, it points to first one spot and then another in the heavens. The pole star is the one which hangs directly over the north pole. Because of the motion of the precession, a number of different stars play the role of the pole star.     Our globe is surrounded on all sides by the star studded heavens. From our place on the face of the earth, we look up at one view of outer space. But our world is moving, and as it moves we move with it to face a different view of the heavens. The heavenly bodies rise and set each day and night as the earth rotates. The changing constellations appear throughout the year as the earth revolves around the sun.     The earth's rotation speed varies from 1000 miles an hour at the equator to Nothing at the poles. The orbital speed is a little faster in December when the Earth is closer to the sun. The average speed at which we circle the sun is 66,600 miles an hour. The average speed at which the solar system whirls through the galaxy is 612,000 miles an hour.