AreciboMessageStephen Battersby writes in New Scientist:

The cosmos is quiet. Eerily quiet. After decades of straining our radio ears for a whisper of civilisations beyond Earth, we have heard nothing. No reassuring message of universal peace. No helpful recipe for building faster-than-light spacecraft or for averting global catastrophes. Not even a stray interstellar advertisement.

Perhaps there’s nobody out there after all. Or perhaps it’s just early days in the search for extraterrestrial intelligence (SETI), and we’re listening to the wrong star systems or at the wrong wavelengths.

There is another possibility, says Douglas Vakoch, head of the Interstellar Message Composition programme at the SETI Institute in Mountain View, California, which ponders the question of how we should communicate with aliens. “Maybe everyone’s listening but no one is transmitting. Maybe it takes an audacious young civilisation like ours to do that.”

So should we start sending messages into the void? And if so, how can we make ourselves understood to beings we know nothing about?