The distance to other stars is so vast that their position in relationship to each other and the earth appears to remain fixed. Thus, we see the same star-patterns appear and disappear in the sky at the same positions and times, year after year. Since the earth also rotates westerly to easterly on its axis, about every 24 hours, as it concurrently revolves around the sun, the stars appear to rise and set from easterly to westerly about four minutes earlier each night. Some stars appear to form definite patterns which are called constellations.
Planets: Our earth is one of nine known planets revolving around a central star--the sun--which comprises what is called the Solar System. Whereas other stars are distant hot self-luminous bodies of nuclear-fired gases, the planets within our solar system are close and cooler bodies which glow from reflected sunlight. Unlike stars, the planets exhibit real observable motion as they journey around the sun with our earth at various distances and speeds. Planets appear to move along a certain band of star patterns or constellations called the Zodiac. The rotation of the earth also causes planets to appear to rise and set easterly to westerly. The bright planets, Venus, Mars, Jupiter and Saturn are often reported as UFOs. Planets shine with a steadier light than stars.
Although bright stars and planets account for a large segment of reported UFOs, their predictable positions in the sky usually allow for an easy identification by a knowledgeable investigator. A series of charts are provided in Section XI to assist the investigator in this respect.