You are looking at a terminator, but this is not a futuristic cyborg. In astronomy, a terminator is the boundary line separating day from night on a planet or satellite, in this case Earth.

This line was imaged by the Apollo 11 astronauts on 24 July 1969, four days after Neil Armstrong and Buzz Aldrin set foot on the Moon. On that day, Armstrong, Aldrin and Michael Collins completed their eight-day lunar mission and made a safe landing in the Pacific Ocean.

After more than 20 years of uninterrupted presence in space, we are now making preparations to return humans permanently to the Moon.

Image description:

A photograph of a crescent-shaped Earth seen from space. In this special image, only the daytime part of the Earth is visible - a thin slice that arcs down and to the right across the image. White clouds, glowing seas and small patches of land can be seen.

 

Credit: NASA

What did you feel when you looked at the border line from day and night?