It is a 24 hour observation of all of the large aircraft flights in the world, (recorded by the 'plane flight transponders, via Geo-stationary orbital satellites), patched together and condensed down to about a minute. (viz. what you see is 24 hrs duration compressed into 1 minute).
From space we look like a beehive of activity. (That's 'cause we are a beehive of activity!!)
You could tell it was summer time in the north by the sun's footprint over the planet. You could see that it didn't quite set in the extreme north and it didn't quite rise in the extreme south.
We are taught about the Earth's tilt and how it causes summer and winter and have had to imagine just what is going on, now the "tilt" is visible.
With this 24 hour observation of aircraft travel on the earth's surface we get to see the daylight pattern move as well across the face of the planet.
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