An alien civilisation has discovered our planet. They were concerned that just suddenly revealing themselves would create a massive shock to the world. By chance, they discovered Geocaching activity. They decided the best idea to introduce themselves would be to hide a cache which could then be found by a limited number of responsible people.
So, they hid a cache and broadcast a message which, by chance, I was able to receive. It took a lot of work decoding it, but I finally managed to get a resolvable image out of their data. I can only assume it is describing the location of the cache they have hidden, but bear in mind they won't have any knowledge of the coordinates system we use. I guess they have been observing us for a long time and for reference used something that is visible from space and has been around a long time. Also, their numbering system is probably different from what we normally use.
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Concept and design for this puzzle is copied with permission of dogastus, based on their cache
First Contact