Since the advent of radio and television broadcasts, humans have been sending chatter deep into the cosmos, ranging from Orson Welles' War of the Worlds broadcast to the latest Jersey Shore masterpiece. But is anyone out there listening? No one has a definitive answer to that question, but a team of researchers has unraveled what kinds of signals that aliens are most likely to see (we can only hope that Jersey Shore flies under their radar). Additionally, relatively close alien eavesdroppers could detect our signals with a radio telescope as big as one soon to be built on Earth, according to the team's paper on the ArXiv. Ironically, aliens are more likely to see our accidental signals from TV, radio and radar than our intentional, direct messages. So why do these accidental signals survive, and what sort of message, if anything, should we be sending into the unknown? The Arecibo Observatory, where messages to alien worlds have been sent in the past.
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