[libertylover]

WOW! WOW-EE ZOY=EE!!! (Full disclosure: I have no idea of the meaning and/or significance of those numbers, but I might be impressed if I had the slightest clue as to their meaning, ha, ha.)

[NorthMountain]

The significance of those numbers is a persistent, highly directional signal much stronger than background. The old “Big Ear” radiotelescope was steerable in only one axis; it used the Earth’s rotation to scan in the other direction. It lost the signal when Earth rotated it away from the source. Subsequent studies of the same area have not detected anything. Although the signal was highly unusual, and definitely of extraterrestrial origin, its cause remains unknown.

[DoodleBob]

Here's a simple explanation, per Wikipedia.

The signal intensity was measured as signal-to-noise ratio, with the noise (or baseline) averaged over the previous few minutes. The signal was sampled for 10 seconds and then processed by the computer, which took 2 seconds. The result for each frequency channel was output on the printout as a single alphanumeric character, representing the 10-second average intensity, minus the baseline, expressed as a dimensionless multiple of the signal's standard deviation.

In this particular intensity scale, a space character denoted an intensity between 0 and 1, that is between baseline and one standard deviation above it. The numbers 1 to 9 denoted the correspondingly numbered intensities (from 1 to 9); intensities of 10 and above were indicated by a letter: "A" corresponded to intensities between 10 and 11, "B" to 11 to 12, and so on. The Wow! signal's highest measured value was "U" (an intensity between 30 and 31), that is thirty standard deviations above background noise.