Only 50 years ago mankind had never seen the view of the Earth from space. Probably the most famous groundbreaking image was the one taken by Apollo 8 astronauts on their way to the moon in 1968.
The impact of this first image was predicted by British Astronomer Fred Hoyle in his book "The Nature of the Universe" in 1955. He said
"Once a photograph of the Earth, taken from outside, is available, we shall, in an emotional sense, acquire an additional dimension.
. . . . and a new idea as powerful as any in history will be let loose. And I think this not so distant development may well be for good, as it must have the effect of exposing the futility of nationalistic strife."
More recently NASA's Messenger probe (on its way to Mercury, via a very extended route) has returned these pictures of the Earth taken on it's recent flyby. Even though we have moved on 50 years I think these new images are no less thought provoking if you take a moment to think about them.
Image: NASA. Click Image for larger version. Or here for a labelled version
The red-brown color on the image on the right is due to the image including infrared light. Trees and plant reflect most of the infrared light falling on them and hence areas of heavy vegetation (South American rainforest in this case) appear reddish.