Most artificial satellites travel in one of the three types of orbits shown here. A <I>high altitude, geosynchronous orbit</I> is above the equator at an altitude of about 22,300 miles (35,900 kilometers). A <I>sun-synchronous, polar orbit</I> passes almost directly over the North and South poles several hundred miles above the earth. A <I>low altitude orbit</I> is in an almost airless level of the atmosphere that begins about 300 miles (480 kilometers) above the earth.
<BR><P>
World Book illustration by Ken Tiessen, Koralik Associates</P>
</BODY></P>
<!-- <PT>YES -->
<!-- <AR>From The World Book Multimedia Encyclopedia (TM) (c) «date» World Book, Inc., 525 W. Monroe, Chicago, IL 60661. All rights reserved. -->