Marathon is a Scale 1 on the Bortle Light Pollution Scale. What does that mean? It's dark! As a matter of fact, as dark as it gets without going to space!
Scale 1 properties:
Excellent dark-sky site
- Naked-eye limiting magnitude:
7.6 - 8.0
- Stellar limiting magnitude (with 12.5" reflector):
• the Zodiacal light (sunlight reflecting off space dust and comet debris after sunset) is visible
• the gegenschein is visible
• the zodiacal band is visible
• M33 is a direct vision naked-eye object
• Scorpius and Sagittarius regions of the Milky Way cast obvious shadows on the ground
• airglow is readily visible
• Jupiter and Venus affect dark adaptation
• surroundings are basically invisible.
(Inset: Light pollution map of southern Texas)