Observing basics
光污染
Light pollution
Artificial light brightening the night sky and hiding faint objects.
In a Bortle 8 city sky the naked eye stops near magnitude 4.
Related terms
- Solar eclipse — The Moon covering the Sun.
- Lunar eclipse — The Moon passing into Earth's shadow.
- Zodiacal light — Sunlight scattered by interplanetary dust, a faint cone.
- Air mass — Relative air path; 1 at zenith.