How do you tell the difference with the naked eye between a star, a planet and a satellite?

Under typical observing conditions, planets do not twinkle while stars do. Also, planets are found along a thin band in the sky called the Ecliptic which passes through the constellations of the Zodiac.

Satellites have a perceptible movement relative to background stars and are seen near or soon after twilight ends as the satellite passes into the Earth's shadow. They move much much slower than meteors, and it can take several 10's of seconds for them to traverse a distance equal to the diameter of the Moon.


Copyright 1997 Dr. Sten Odenwald
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