The signal was unmodulated — so in other words it did not contain any information apart from its existence.

Its existence alone was interesting enough to professor Dr. Jerry R. Ehman that he wrote "Wow!" upon the paper printout, which Big Ear had recorded several days earlier. Indeed, the so-called "Wow Signal" is as yet the most important radio evidence of anything like extraterrestrial intelligence.

While unmodulated — lacking explicit information — the Wow Signal was conspicuous because it was narrow-band (and thus not "natural,") and because it was powerful.

Transmission at 1420 mhz by terrestrials is illegal by international agreement. This is because the frequency is excellent for observation of the cosmos — its 21-centimeter wavelength passes through many regions of outer-space that are opaque to other electromagnetic frequencies. It is for this reason, also, that 1420 would be a natural candidate for interstellar "hailing-frequency" purposes.

Calculations showed that the Wow Signal originated from beyond the Moon. It is possible that its origin was a device made by Earthlings — nations do break treaties, for example. But it did not come from a legal human-built apparatus, and it did not come from Earth, unless it was deflected by an object in space.

The notation upon the "Big Ear" printout, "6EQUJ5," is merely an alphanumeric representation of a peaking and falling amplitude. The team was making notation using a system of 35 "digits," composed of the numerals 1 through 9 and letters A to Z.

Nobody had ever collected a narrow-band radio signal of such intensity, nor has anybody since.