Patti Sammut, age 11, of Islington, Ontario,Canada, for her question:

Does the moon orbit faster than the earth?

The moon is a captured satellite of the earth. It is held in bondage by the pull of the earth's gravity that forces it to orbit around and around our planet. Meantime the planet and its satellite travel together in a yearly orbit around the sun. Both the moon and the earth circle the sun at an average orbital speed of almost 18 1/2 miles per second. The distance of this yearly orbit is about 600 million miles and the earth and moon pace each other all the way.

But meantime the moon is busy with another orbit. As it circles the sun, it is also swerving in a curved path around the earth. Its orbital speed around the earth is much, much slower than its orbital speed around the sun. The curved path around the parent planet is only about 20 times wider than the distance around the earth's equator. And here the moon takes its time. Its orbital speed around the earth is not quite 0.65 miles per second. Its average orbital speed around the earth is 2,300 miles per hour and its solar orbital speed is 66,600 miles per hour.