Human civilizations dating back thousands of years left behind structures and records documenting their studies of the stars as they sought to chart the seasons, help travelers find their way and interpret the world around them. Stargazers among the ancient Greeks, Maya, Egyptians, Middle Easterners and Asians likely also pondered if there were other planets like ours among those distant points of light — and if so, what might live there.
http://www.livescience.com/59153-how-to-search-for-extraterrestrial-life.html
