# Transparency

Also called: clarity, haze.

How clear the air is: on a transparent night faint stars and galaxies show; haze, humidity and dust hide them.

Transparency is about how much light gets through: thin high cloud, humidity, haze, dust and smoke all dim faint objects and scatter town lights into a brighter sky. It matters most for faint galaxies and nebulae; planets barely notice.

A sky can be transparent but turbulent, or murky but steady — so a bad deep-sky night can be a good planetary night, and vice versa.

**In AstroPilot:** Hour by hour on Tonight rates transparency from 1 to 5 from humidity, high cloud and aerosols.

**Related:** [Seeing](https://astropilot.space/glossary/seeing.md), [Aerosols](https://astropilot.space/glossary/aerosols.md), [Cloud cover](https://astropilot.space/glossary/cloud-cover.md), [Extinction](https://astropilot.space/glossary/extinction.md)

From the AstroPilot astronomy glossary: https://astropilot.space/glossary/transparency