When they look at sky brightness—what they call the sky background—they use a unit of brightness per area of the sky: how much light is spread out over a given parcel of celestial real estate.

It won't be easy though. Besides having to contend with the twilit sky background, Neptune — appearing as a tiny bluish star — will be about 63,000 times dimmer than Venus. You'll have much ...

It also increases the sky background glow, which then makes it much harder to see nebulas, dust clouds, and finer details in the night sky. A brighter night sky poses problems for wildlife ...