By human standards it could not possibly have been artificial: It was the size of a world. But it was so oddly and intricately shaped, so clearly intended for some complex purpose that it could only have been the expression of an idea. Gliding in polar orbit about the great blue-white star, it resembled some immense, imperfect polyhedron, encrusted with millions of bowl-shaped barnacles. Every bowl was aimed at a particular part of the sky. Every constellation was being attended to. The polyhedral world had been performing its enigmatic function for eons. It was very patient. It could afford to wait forever.
Excerpt from Contact by Carl Sagan