Astronomy - Why Marathons' Skies Are So Special!

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!

Bortle 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.

Southwest Texas Light Pollution Map:

texas light pollution

Current Moon Phase:

NOAA Water Vapor (Updated every 30 minutes) - Courtesy of NOAA.GOV:

NOAA Water Vapor Image

Marathon Clear Sky Chart:

Current Weather in Marathon, Texas