ISS and Soyuz Antennas. Rotation Speed and Earth Movement


Active Member
Hello all!

I stumbled upon a video " Who forgot to spin the Earth ": Source:

Time stamp 11 seconds on wards to a few more seconds we see a mini dish (I do not know what to call it) rotating very fast and the Earth is not in accordance. Where as the ISS feed sometimes shows from the particular cameras nearer that dish which is not rotating that fast but Earth is moving at a faster rate than it was in the video posted by the conspirator. The other videos of ISS feed show that dish rotating not as fast as in the first video but the Earth seems to rotate faster than the first one. Second video: Source:

Sorry, I could not find any other video which does not have that UFO stuff (in live ISS feed it did come up but you will have to wait) going on but it does show the dish rotating and you can see the Earth rotating out of sync.
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Staff member
The rotating dish is the RapidScat antenna, which uses microwaves to measure wind speeds at the surface of the ocean.

The dish rotates at 18rpm, or one revolution every 3.3 seconds.

I must admit I am not seeing what you mean about the Earth's rotation being "out of sync". The footage from 0:11 in the video you mention is clearly sped up a great deal. It is a very wide-angle shot showing a large amount of the visible Earth, so of course the apparent motion seems very little.

Edit: see below, as @Mick West points out, they are different antennae. However it is also the case that the field of view of the two videos is quite different, as in this comparison:

rightside.jpg upsidedown.jpg [/compare]

(I rotated one image upside down to match the horizon positions)
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Mick West

Staff member
They seem to be different antennas. This is the Rapidscat antenna:

This one is not the RapidScat antenna


Active Member
So, the fast moving antenna is the one on Soyuz ( KURS rendezvous radar), which means that the video I attached first was showing the Soyuz? Although field of view is also a reason the Earth's rotation appears to be different. The first video I attached, if you look closely it seems as if the dish's movement is looped. It jerks and stops (for way less then a second) and starts moving again very rapidly; you have to closely look, I am asking just for curiosity what is it?

Edit: I realized it was because I was looking at one of the video in 144p and the other in 720p and the frame rate was 13 and 25 respectively, which caused the antenna to seem to rotate faster and smoother in one and a bit jerky in other.
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Active Member
says who? where is the evidence that the Earth is not in accordance?
I meant Earth's rotation seems slower, but the dish is rotating faster, but now I know it was the different antenna which I was mistakenly thinking of as the ISS's antenna.