as seen on BBC Horizon "strange Signals from outer space" at around 31.41
http://www.bbc.co.uk/iplayer/episode/b08r3xr3/horizon-2017-strange-signals-from-outer-space#
Thanks
http://www.bbc.co.uk/iplayer/episode/b08r3xr3/horizon-2017-strange-signals-from-outer-space#
Thanks
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