The night sky is an inseparable element of wild areas serving as a natural, cultural, educational, and economic resource for wildlife and park visitors. Light from anthropogenic sources, however, causes skyglow that brightens the night sky. Skyglow artificially illuminates the landscape and degrades visitor opportunities to view planets, stars, galaxies, and other astronomical objects. To effectively manage the night sky resource, we need to characterize the current sky brightness and identify the locations of light sources.
The NPS has developed a camera system for measuring sky brightness to quantify the source and severity of skyglow. Each resulting data set yields a 40-million-pixel image mosaic covering the entire night sky from zenith to horizon. This report provides a summary of the measurements and the associated images.
Please refers to the Night Sky Quality Report Guide for interpretation of the metrics and images shown on this page. For details about equipment used, data collection methods, and analysis procedures, please refer to and the Night Skies Data Report: Photometric Assessment of Night Sky Quality—Chaco Culture National Historical Park Natural Resource Report on IRMA references therein.
Park | Site Name | Latitude | Longitude | Elevation |
---|---|---|---|---|
Date (LMT) | Time (LMT Hours) | Observers |
---|---|---|
Air temp. (°C) |
R.H. (%) |
Wind Speed (mph) |
Extinction Coeff. (mag/airmass) |
---|---|---|---|
NELM | Bortle Class | Synthetic SQM | SQM | Percent stars visible |
---|---|---|---|---|
Observed (mag/arcsec2) |
Estimated Artificial (mag/arcsec2) |
Observed (ucd/m2) |
Estimated Artificial (ucd/m2) |
|
---|---|---|---|---|
Zenith | ||||
Brightest | ||||
Mean all-sky | ||||
Median | ||||
Darkest |
Observed (mlux) |
Estimated Artificial (mlux) |
|
---|---|---|
Horizontal | ||
Max Vertical |
Light Pollution Ratio |
|
---|---|
Zenith | |
Brightest | |
Mean All-sky | |
Median | |
Darkest | |
Horizontal | |
Max Vertical |