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What struck me about this was how huge the moon looks compared to the earth. We are used to seeing this as a small object in the sky (after all, it's 2000 miles across and 200000 miles away).

But when viewed from afar...you're seeing an object with an 8K mi diameter and another with a 2K mi diameter, not that different in size at all.

Which, I guess is another way to say: the earth just ain't that big.

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These pictures were taken "only" 1,000,000 miles away, so the Moon is significantly closer to the camera than Earth was, which makes it appear larger compared to Earth than it really is. The true size comparison is more like [0]. The effect is also more because the

[0] http://qph.is.quoracdn.net/main-qimg-5bff56bc0b31f8b7395bdbe...

The relative sizes of objects in a photo like this will vary depending on whether you're close up and using a wider angle lens, compared to being far away with a very zoomy telephoto.

It approaches an "apples to apples" size comparison asymptotically as you move infinitely far away with an infinitely zoomed lens.

For a quick illustration: http://i.imgur.com/zME26IW.png

When you're up close, the moon obscures a much larger portion of the Earth, even though they're not changing size.

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