light-line

Updated: June 21, 2025

Before, from the orbit-ship, he had been able to see only the bright side of the huge rock; now he could see the sharp line of darkness across one side. But there was something else.... He fired the bumper again to steady himself, peering into the blackness beyond the light-line on the rock. He snapped on his helmet lamp, aimed the spotlight beam down to the dark rock surface.

Alan Edward Nourse - Gold in the Sky