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If the Earth is spinning or rotating at a really fast speed, why haven't we seen any videos from space of it spinning when we get a lot of photos of it?

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""If the Earth is spinning or rotating at a really fast speed,.."" What is "fast speed" for You? One rotation in 24 hours? Rofl –  Georg Oct 4 '11 at 19:09
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5 Answers 5

up vote 8 down vote accepted

First of all, let's calculate the rotational velocity of the Earth, at the equator. The diameter of the earth is 12,756 km. Therefor, the speed is ${12,756km*\pi}/{24 hrs}=1669 km/hr$.

Given that we know the rate of spin of the Earth, what else would be required to see this change?

  1. The point of reference would need to be relative to the Sun, or possible the Earth-Sun system, but not LEO like most spacecraft are. Geosync. orbit would not work either, as the satellite is moving at the same speed as the Earth. A very high orbit might work, such as the Moon would be in.
  2. In order to achieve 1, a significant distance from the Earth is required.
  3. Given that a large distance is required, the Earth will not appear to be moving as quickly as it would otherwise.

Just to compare this, I pulled the speed of the moon orbiting the Earth from wikipedia. That speed is 1.022 km/s, or about 3,680 km/hr. That is a much higher speed than the Earth rotational speed. Given that the distance requirements are similar to see the rotational speed of the Earth, it seems that one would have to notice the moon orbiting if one could notice the rotation of the Earth, in real time. (Note, it's a bit easier to see the Earth rotating, due to the easy comparison, but...)

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I put your figures into a calculator amd got 12,756×3.14 =40,053.84 40,053.84÷24 =1,668.91 did you make a mistake or is it me? –  Jitter Dec 30 '13 at 17:42
    
@Jitter: Not sure what I did, but I think you are right... –  PearsonArtPhoto Dec 30 '13 at 18:39
    
It happens to all of us;-) I'd like to hear the excuses from the 7 people who upgraded you before the edit. –  Jitter Dec 30 '13 at 19:12
    
On SO I have an answer to one of my questions that has 10 upvotes and doesn't even remotely work, and on SO you can actually test it fairly easily, so... –  PearsonArtPhoto Dec 30 '13 at 19:17
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Well it is quite expensive to go into space and so taking a video camera for some holiday snaps is not exactly a high priority.

However weather sattelites do exactly this with images of cloud formations and movements. Obviously these aren't typically very glamorous so rarely make into the public domain.

However they did recently take a camera on board the ISS

APOD sept 27 2011

rather pretty I think!

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More importantly, in order to see the rotation properly, you'd need to stay at the same relative point in space. But in order to orbit the Earth, you typically need to go around it faster (until you get to geosynchronous orbit). The video's from the ISS make the Earth look like it's spinning because the ISS is orbiting so quickly. (It's mean orbital time is about 90 minutes.) I guess if the Apollo astronauts had taken a video recording of the Earth, from the moon for just over a day, you'd see about one full revolution of the Earth. But as said, that wasn't exactly a high priority: it's not like we're in any doubt that the Earth rotates once per day!

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Right we're not in any doubt but we always get sooo many cool photos of space from NASA, and who wouldn't want to see a video of the Earth spinning? That's something no body's ever seen before. If they can take a photo camera up there, I don't think it would be that difficult to press a record button, don't you think? That's why I was thinking it's a bit odd we don't see a video like this. –  maq Oct 4 '11 at 14:09
    
The I'm not sure if the video in @Nic's answer is what you're actually looking for? You question asked about the Earth's rotation, which isn't what the video shows, but it does fit the description of taking a camera up and pressing record. –  Warrick Oct 4 '11 at 14:40
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This video shows the Earth spinning at high speed, as seen out of the window of one of the space shuttles.

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is this video true ? –  Aravindhanarvi Oct 6 '11 at 11:00
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You know I have been asking this same question, why aren't there videos of the earth's rotation from space? I've searched and only have found the opposite. Dish network had a station called "dish earth" that was up for about 3 years. Now if you select the 'dish earth' channel it will give you a different channel/station, NASA. What's really interesting is for a good 3 years this station showed a non-rotating earth in space and if you were to record it for a day, speed it up a bit, you will see the sun revolving around the earth and there's no playing around with it! Youtube have a few of these videos posted by people who had "dish earth". There's no mistake about it. In maybe 2 of those videos you will also see the moon passing by as well.

Even some of the videos from the ISS can support a non-rotating earth, look up sunrise or sunset in space on youtube.

Sometimes seeing is believing and all the math equations in the world can't alter reality. If there can be visual evidence of the earth's rotation, we would have had it long ago, there's no doubt in my mind.

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