User:Vivek bhati1990

'wow signal 

It’s no rare occurrence in science fiction: The introverted researcher working the graveyard shift at a SETI radio observatory jumps out of his seat in surprise when the red light blinks on the control panel. “We’re getting a signal!” he shouts into a phone as needles dance across paper chart recorders, and scientists rapidly converge on the scene. At some point someone yells, “Get me the President!” at the person whose job it is to get presidents.

On August 15th, 1977, such a signal was received at the Big Ear radio observatory in Ohio, though the ensuing drama was considerably more subdued. The volunteer who spotted the pattern on the paper logs circled the data and wrote “Wow!” in the margin. The radio telescope was observing space as part of the Search for Extra-Terrestrial Intelligence (SETI) program, and it was the most compelling signal the receiver had recorded in its fourteen years of operation. It was powerful enough to push the Big Ear’s monitoring device off the charts.

The signal came from the direction of the constellation Sagittarius, and lasted seventy-two seconds at about 1420.4range of frequencies it appeared in. Seventy-two seconds also happened to be the exact length of time it would take for the Earth to rotate the Big Ear through a signal from space. He did some analysis of the data, and by all indications this powerful, narrowband radio signal was from outside of our solar system. But was it sent by an advanced civilization?

Curiously, the signal was picked up by only one of the scope’s two detectors. When the second detector covered the same patch of sky three minutes later, it heard nothing. This indicated either the unlikely possibility that the first beam had detected something that wasn’t there, or that the source of the signal had been shut off or redirected in the intervening time. The observatory researchers trained their massive scope on that part of the sky for a full month, watching closely for a repeat of the mysterious signal. Nothing interesting was observed during those thirty days, yet scientists were at a loss for an explanation of the original event. Planning to return to that patch of sky periodically, the Big Ear continued its broader purpose.

Several times over the next twenty years, longtime SETI researcher Robert Gray and his colleague Kevin B. Marvel arranged for further scans of that region of space. They managed to obtain some time on the META array at the Oak Ridge Observatory in Massachusetts, and the extremely sensitive Very Large Array (VLA) in New Mexico, which is made up of twenty-seven 25-meter radio dishes. They detected some extremely faint sources of radio emissions in the infamous patch 56 MHz before it faded away. The volunteer who found and circled the data in the paper printout was Jerry Ehman, who was amazed at the signal’s intensity and what a narrow