One or both of those Voyager's are headed out of the solar system with recorded greetings from Earth for intelligent beings from other planets outside of our solar system to listen to (in about 50,000 years from now, maybe). How would we describe our location in the Universe to them so that they would know where to look in the nighttime sky??
Posts: 625 | Location: Boston | Registered: 06-13-02
I'm assuming you're assuming we don't know where the aliens are viewing us from. If we did, it would be as easy as pointing and giving a distance.
otherwise...
In three dimensional space, you need 3 coordinates. Referencing to any particular star by its properties won't work because there are too many similar ones. Referencing a constellation won't work because they won't have the same perspective on it and most likely won't see anything special about the same group of stars from their planet.
An obvious reference point is the center of the galaxy. Another is the distance above the center of the disk stretching out from the galactic center. I would choose one of the arms of the galaxy as the third reference point, but there's probably sometihng better.
of course, since everything is moving relative to everything else, there would have to be some time reference as well.
