Eavesdropping on Alien Chatter




Extraterrestrial probes exploring the galaxy could be using stellar bodies as transmission towers, a recent study suggests. On Earth, the placement of telecommunication towers and satellites serves to keep us connected with each other and relay information relatively efficiently. On cosmic scales, however, the issue of data transmission becomes tricky. The vast distances a signal needs to travel in order to convey useful information without significant attenuation could present an advanced civilization with insurmountable connectivity issues. Can you hear me yet?

Thankfully, interstellar alien probes scouting the cosmos can make use of "gravitational lensing" - a well-known relativistic phenomenon - to solve and boost their broadcasting range issues without incurring in expensive roaming charges. As many of you know, massive bodies affect spacetime in weird ways that are more or less well-understood. In the case of gravitational lensing, any radiation passing near the vicinity of a heavy object, such as our sun, gets amplified and focused. This naturally-occurring effect is just what is needed to transmit a signal to a remote location on the cheap.

Since every star is in essence a communications node, a group of researchers at Penn State University wondered whether aliens might be actively using the signal-amplifying properties of our sun and other nearby stars to transmit information back to their home world. To this end, the collaboration used the Green Banks Telescope - the world's largest fully steerable radio telescope - to listen for alien chatter. The surprising results can be found in the link below.