I went to the local astrosoc last week and the talk was on the Solar System. It was pretty good. Real old timer giving it.
He made a comment about a photograph of Earth.
When he was a lad, being taught astronomy in school, there were none of the great pictures of anything we now take for granted. Instead, the teacher showed him "the Earth" by showing a map. So he remembers growing up thinking of "the Earth" as a rectangle with these shapes on. Many of the shapes were purple, that was the British Empire. Some of the shapes were yellow, that was the German Empire. Some of the shapes were green, that was the Dutch Empire. And so forth.
Nowadays though, when kids are taught astronomy, they are introduced to the Earth by a photograph of the blue and green orb. Kids grow up thinking of the Earth as a planet, not as a map of territorial control.
That is progress.
He added that this benefit of the photo justifies every penny spent to acquire it.
He did briefly segway into a moan about Dorset County Council though.