The 100-m Green Bank Telescope in Virginia has just picked up a strange radio signal, originating from KOI 817 (with KOI standing for Kepler Object of Interest) that looks as if an alien civilization is transmitting to us. SETI is excited as this is the type of radio signal it would expect from an alien civilization.
Not from an alien world
However, before the excitement can get too wild, SETI says that this signal is definitely terrestrial, rather than extraterrestrial. The signals have “terrestrial radio frequency interference” or RFI. Right now, the signals are a great source for SETI astronomers to study radio-frequencies, should they encounter a radio-emitting alien civilization.
The radio signals are narrow in frequency range (photo above), much narrower than anything that would be produced by an astrophysical radio source. The frequency of the signals is also perfect! Even the Doppler shift is just right, with the frequency decreasing at the precise rate expected from the relative motion of the transmitter and the receiver. A team from UC Berkeley has this to say:
These signals look similar to what we think might be produced from an extraterrestrial technology. They are narrow in frequency, much narrower than would be produced by any known astrophysical phenomena, and they drift in frequency with time, as we would expect because of the Doppler effect imposed by the relative motion of the transmitter and the receiving radio telescope
Kepler has been remarkably successful in detecting exoplanets. It has achieved much success by looking at ‘transits’, or the passage of planets in front of their suns. Kepler needs four transits to confirm the existence of an alien planet. This takes around 3.5 years.
So, tantalizing it might seem, but it’s just not true. Kepler has not yet found alien life, leave alone intelligent alien life. But the search continues…