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Sunday, October 1, 2017

Zig Zag

Aircraft leaving zig zag contrails over the Arecibo radio telescope
I came across this while I was mapping Big Antennas, and I wondered what could have caused the contrails to zig zag like that? Are there narrow bands of contrary winds blowing north and south? Is the plane following the conture of the ground while flying over hills? Neither of these explanations seemed likely.

Aircraft leaving straight contrails over the Arecibo radio telescope
Then it struck me that is was likely an artifact of Google's imaging program, and sure enough, change to the 3-D view, spin the orientation 180 degrees and tilt the view a little bit and those contrail lines straighten right out.

2 comments:

  1. ObRant : The Astrophysicist are trying to receive the weakest of signals, which is not helped by planes flying nearby, with their much stronger radio signals (aka interference), just because the pilots want to give their passengers something to look at :-(

    It would be better to make this Prohibited Airspace for a few miles around, imho.

    There is a movable large radio telescope in the Eifel mountains near here; you are not allowed to drive your vehicle within a mile, to minimise interference from the vehicles electronics (e.g. sparking plugs).

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  2. I think Arecibo is shut down. Or maybe radio telescopes don't work during daylight hours, too much interference from the sun?

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