Moving in space

Home Rockets Gravity Kepler's laws

The moon and satellites orbit the earth.  The earth and other planets orbit the sun.  What determines the motion of these objects in space, and can this motion be changed?

This image was captured by the Galileo spacecraft in 1992 as it flew by Earth at a distance of 6.2 million km (3.9 million miles).  The Moon is passing in front of the Earth.  Earth's gravity is the force that holds the Moon in its counterclockwise orbit (the Moon will pass from left to right in front of the Earth as seen in this picture).