Wow! Signal - Speculation On The Signal's Origin

Speculation On The Signal's Origin

Interstellar scintillation of a weaker continuous signal—similar, in effect, to atmospheric twinkling—could be a possible explanation, although this still would not exclude the possibility of the signal being artificial in its nature. However, even by using the significantly more sensitive Very Large Array, such a signal could not be detected, and the probability that a signal below the Very Large Array level could be detected by the Big Ear radio telescope due to interstellar scintillation is low. Other speculations include a rotating lighthouse-like source, a signal sweeping in frequency, or a one-time burst.

Ehman has stated his doubts that the signal is of intelligent extraterrestrial origin: "We should have seen it again when we looked for it 50 times. Something suggests it was an Earth-sourced signal that simply got reflected off a piece of space debris."

He later recanted his skepticism somewhat, after further research showed an Earth-borne signal to be very unlikely, due to the requirements of a space-borne reflector being bound to certain unrealistic requirements to sufficiently explain the nature of the signal. Also, the 1420 MHz signal is problematic in itself in that it is "protected spectrum": it is bandwidth in which terrestrial transmitters are forbidden to transmit due to it being reserved for astronomical purposes. In his most recent writings, Ehman resists "drawing vast conclusions from half-vast data"—acknowledging the possibility that the source may have been military in nature or otherwise may have been a production of Earth-bound humans.