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For reasons unknown, I started pondering what cities/towns in Sweden and Australia are the closest to each other. My hunch was that some town in the South such as Malmö or Karlskrona would be closest to some town in the North(west) of Australia such as Broome.

Exploring the matter using greatcirclemap.com told me a different story - the closest town (airport) I could find was Pajala in the very North(east), which is closer to Darwin in the middle of the Australian North than to towns like Broome in the Northwest or Perth in the far West.

Is there a simple, intuitive explanation for this fact? What is a good way to make educated guesses about great circle distances? How can Pajala be closer to Australia than Malmö, being about 1350 kilometers farther north but only 350 kilometers farther east?

Toivo Säwén
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As some comments suggest, nothing substitutes for a globe and a tape measure. But there is a subtle hint of the outcome.

Australia is southeast of Sweden according to latitudes and longitudes, but that means little on a spherical Earth. The latitude of Mecca is south of Chicago's, but mosques in the latter city are built to facilitate the Muslim patrons facing north-east, along the Great Circle route which (in the Northern Hemisphere) deviates north from the compass direction.

In the case of Sweden, that country is so far north that the "northern deviation" of Great Circle routes to distant lands around the Pacific Ocean carries that route near the North Pole itself. Then we may well expect northern Sweden, being closer to the North Pole, to be closer to those far-off destinations.

Oscar Lanzi
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  • Cool, so you mean you have two legs on a great circle over the pole, one from the pole to the destination which is fix, one from border of the country you started to the pole. Nice idea, if it helps :-) –  Sep 22 '23 at 11:23