If there is life beyond our planet, how would we able to communicate with it? In Star Trek, starships communicated with each other using a vast network of transmitters, relay stations, relay antennae and relay satellites that sent visual, voice and data signals at faster-than-light speeds through a medium called sub-space. The Star Trek producers had to send 'hailing frequencies' over these faster-than-light 'sub-space channels' for the simple reason that sending signals over 'normal' space would just take too long.  Today, all of our broadcast signals—radio, television, microwave, radar, and light—travel at the speed of light (about 300,000 kilometers per second). Any signals we would send to even the nearest star to our sun, Proxima Centauri, would take 4.2 years to reach it.

Has Earth detected any signals from beyong the solar system yet? Not conclusively. There have been interesting "candidate" signals found. The Ohio State Big Ear radio telescope made history in August 15th, 1977 by detecting an extremely strong, narrowband radio signal that, after ruling out terrestrial sources and known artificial satellites, bore expected hallmarks of potential non-terrestrial and non-solar system origin. Astounded at how closely the signal matched the expected signature of an interstellar signal, the researcher who detected it - Dr. Jerry R. Ehman - circled the signal on the computer printout of the results and wrote the comment "Wow!" on its side. The signal lasted for exactly 72 seconds and is thought to have originated from a region of the sky in the constellation Sagittarius, roughly 2.5 degrees south of the fifth-magnitude star Chi-1 Sagittarii.

The "Wow" signal remains the most intriguing clue to intelligent life beyond our solar system, but it has not been heard again since.

The Wow" signal: The circled letter code 6EQUJ5 describes the intensity variation of the signal. The value 'U' (an intensity between 30.0 and 30.999) was the highest ever detected by the Big Ear telescope.