This section is a discussion concerning the types of natural phenomena commonly reported as UFOs to aid the investigator in evaluating UFO sightings under investigation. The transparent sky is like a window through which we look out upon the universe in different directions and see changing scenery along the way. 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.
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.