[link to www.cropcircleconnector.com] <--- this!

Search for the constellation which looks like the one on the right part of the image. When sun (or moon) is near it like that, and the planets of our solar system is like on the left part (use astrolabe program), you can find the planet (where they are sending this information - the ball in the end of the cord) at that direction then.

Or perhaps that is when they have sent the message. Dunno. Anyone?