Sky Quality Meter (SQM)
The "Sky Quality Meter" measures the brightness of the night sky in magnitudes per square arcsecond.

Latest Reading

Chart of Recent Readings

Chart of Recent Readings
Uses:
- Find out how good the night REALLY is.
- Compare the sky brightness at different sites quantitatively.
- Document the evolution of light pollution in our area.
- Monitor sky brightness through the night, night-to-night, and year-to-year.
- Determine which nights show the greatest promise for finding the 'faintest fuzzies'!
- Investigate how sky brightness correlates with the solar cycle and month-to-month sunspot activity.
- Help provide local ground truth for future sky brightness prediction with the Clear Sky Clock.