Oh, well

After a 10 year program looking closely at 800 nearby stars for some kind of radio signals that could indicate the presence of intelligent life on planets possibly circling them, Project Phoenix has come to an end with the conclusion "We live in a quiet neighborhood."

Much of the effort's time was spent using the world's largest radio telescope at Arecibo, Puerto Rico. There, they did a planned, close scan of a particular swath of sky and nearby stars within it. ("Nearby" is a relative term in astronomy: After the sun, the next nearest star is Proxima Centauri, about 4.3 light years away. That is, it takes light from that star nearly 4-1/2 years to get here. In more familiar but here less useful units, 4.3 light years is about 25 trillion miles or 40 trillion kilometers.) They found nothing that couldn't be ascribed to an Earth source or interference.

However, SETI (search for extraterrestrial intelligence) researchers haven't given up: Next year they intend to start a new search with the Allen Telescope Array, a collection of 32 small radio telescopes electronically linked so they can act as one large one. The intention is to continue to expand that array, in effect making a more and more sensitive telescope that can look for weaker signals from farther away. The plan involves a targeted search of several hundred thousand stars as opposed to the 800 from Project Phoenix.

As the searchers recognize, it's possible such a signal will never be detected. It's possible that there literally is no one out there; it's more possible that there's someone out there but they're not producing signals we can detect, either from lack of intelligence, lack of technology, or just lack of interest. But, as the searchers also recognize, we'll never know if we don't look.