The Distant Earth
The following page is based in part on the original work by Count Zero which can be found in the forum here: The Smoking Gun of Bart’s “Smoking Gun” Footage.
Many of the images taken by the Apollo astronauts show the Earth from a great distance. The images show Earth as a globe, with entire continents visible, rather than the much narrower field of view seen from low Earth orbit.
A spacecraft in low Earth orbit (LEO) would orbit the Earth in about 90 minutes, which would mean one minute they could be over North America, and then a short time later they could be over Europe or Australia. Because of this, the view of the Earth changes quickly. An astronaut traveling to the Moon, on the other hand, would see the same view of Earth for much longer than they would in LEO. While they are still orbiting the Earth, the orbit is more elliptical and takes them away from the Earth.
But how do we know these images were taken by astronauts, and not unmanned satellites? Well, because during the journey to the Moon, the Apollo 11 astronauts made three television broadcasts. During these broadcasts they shot video of the Earth through the window. Therefore, we have both the distant Earth and the astronauts in the same video.
Conspiracy theorists make the claim that the images of the Earth could be artificial backdrops, like Hollywood uses for big budget science fiction movies. But there are many ways you can tell that this is not the case.
For example, compare the following two images. The first is a photograph of Earth from Apollo 11, and the second is a precipitation map for North America from the same day:
File: Weather_14-19_jul_1969.pdf
You can see many similarities between the precipitation map and the cloud cover in the photograph. NASA could not have prepared any kind of artificial backdrop with that kind of accuracy. And accuracy would have been necessary if such a hoax was to succeed.