It's called the "Terminator," the margin on the Earth between day and night. From 35,000 feet, it appears as a dark blue line on the horizon, just as the sun starts to set, and it slowly expands, growing in height, until you're enveloped in the black dark of night.
It's called the "Terminator," the margin on the Earth between day and night. From 35,000 feet, it appears as a dark blue line on the horizon, just as the sun starts to set, and it slowly expands, growing in height, until you're enveloped in the black dark of night.