The darker the sky, the more stars can be seen. The following simulated images depict how the constellation Orion appears under various sky conditions. Images are courtesy of GLOBE at Night. How good is your sky at home?
Limiting Magnitude=2. This is typical of an urban sky. The constellation Orion is not completely visible,
and most would have a difficult time finding it in the sky. Only about 50 stars can be counted from dusk till dawn.
Bright planets and a few bright shooting stars (meteors) may also be visible.
Limiting Magnitude=4. This is typical of a suburban sky. The constellation Orion is now visible and the bright stars of
Betelgeuse, Rigel, and Aldebaran stand out clearly. About 500 stars can be counted from dusk till dawn.
Limiting Magnitude=6. This is typical of a rural sky, far from big cities or just outside of a small town.
Constellations are brilliant and the night sky appears almost black. The Milky Way, our own galaxy seen edge on,
is obvious overhead. Meteors are seen throughout the night and you may catch a glimpse of the Orion Nebula or
Andromeda Galaxy without the aid of a telescope or binoculars. Perhaps 5000 stars can be seen.
Limiting Magnitude=7. This is a truly dark sky, far from major and minor light sources. From dusk until dawn,
about 15,000 stars can be counted. Constellations are almost lost against a bedazzled sky. The Milky Way can cast
a shadow and appears detailed, filamentary, and marked with dark veins. Venus and Jupiter are bright enough to interfere with night vision and cast a shadow. The sky looks three dimensional and stretches firmly to the horizon without interference from light pollution.