After decades of fruitless scanning the skies for alien messages, scientists say it's time to try a basic rule of etiquette: Say "hello" first.
A San Francisco-based organization called METI, or Messaging Extra Terrestrial Intelligence, plans to send signals to distant planets, rather than waiting for them to call Earth.
By the end of 2018, the project aims to send some conversation-starters via radio or laser signals to a rocky planet circling Proxima Centauri, the nearest star other than the sun, and then to more distant destinations, hundreds or thousands of light-years away.
It would be the first effort to send powerful, repeated and intentional messages into space, targeting the same stars over months or years.
"If we want to start an exchange over the course of many generations, we want to learn and share information," said Douglas Vakoch, president of METI and former director of Interstellar Message Composition at the Search for Extraterrestrial Intelligence Institute, known as SETI.
Like much else in science, the project has turned controversial. Some ask: If aliens are hostile, do we really want them to know where we are?
We shouldn't draw attention to ourselves, say science fiction writer David Brin and theoretical physicist Stephen Hawking.
Others endorse the effort. "I'd be happy to see this done," said Seth Shostak, senior astronomer with the SETI Institute. "I think there's something to be learned, nothing to be feared, and at least the possibility of discovering something truly revolutionary: We have company nearby."
