This game uses annual VIIRS nighttime radiance values for 2025.

• Higher values mean more artificial light is being emitted upward and picked up by the satellite near that city coordinate.
• The source is a point sample, not an average over the whole metro area.
• This is closer to visible glow from space than to a full street-level or stargazing darkness score.

Bright on the map does not always mean livelier on the ground. It means more light leaving the surface.