Guides & understanding
Make more of your night.
Start with the sky, the forecast or your first measurement.
Explore the sky
Meet the planetarium.
Find a star or planet, change the time and switch sky layers. The atmosphere toggle compares a reference view with a model estimate.
Open planetarium →Understand conditions
Read the forecast.
Learn how haze, moonlight and skyglow affect what you can see.
Method & physics →Measure your sky
Take an SQM reading.
Use a repeatable routine, record the conditions and share your observations.
Measurement guide →Submit a reading →