What is ‘The Wow!’ signal?

If you are a distinguished member of the “I think about extraterrestrial life all the time!” fraternity and don’t know about ‘The Wow!” signal, then you have some catching up to do.

E.T

Evolved from the ideas of the ‘alien’, the SETI or Search for Extraterrestrial Intelligence is the endeavour — diverse efforts, projects, etc. — undertaken to find signs of life beyond Earth. When the shortwave radio was discovered in the 1920s, scientists realised that we could detect alien intelligence through radio waves. Thus, ever since, SETI research has focused on monitoring radio signals.

Scientists realised that we could detect alien intelligence through radio waves.
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Getty Images/iStockphoto

Ohio and the Big Ear

In 1961, the Ohio University in the U.S., completed the construction of a Kraus-type radio telescope referred to as the “Big Ear”.

What? The telescope has a unique design, designed by Ohio State University’s radio astronomer John Daniel Kraus and hence called ‘Kraus-type’.

Formally known as the Ohio State University Radio Observatory, this telescope, located in Delaware, was part of the university’s SETI project. From 1973 to 1995, under the volunteer-staffed NASA led SETI project, Big Ear searched hard for radio signals that were extraterrestrial in nature, signals that come from alien civilisations.

Big Ear searched hard for radio signals that were extraterrestrial in nature.
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Wikimedia Commons

1977

Astrophysicist Jerry R Ehman was volunteering as an astronomer at the Big Ear Radio Observatory’s SETI project in 1977. Analysing chunks of data that the telescope produced was his task and this meant that he was always looking at values printed on paper through the line-printer.

On 17th August, as Ehman was looking through narrowband signal values from 2 days ago (15th), he noticed an anomalous signal intensity; variation so interesting and strong that Ehman couldn’t help but circle the specific alphanumeric intensity sequence (part of the continuous signal where the intensity was strongest) on the printout and write “Wow!” next to it. Soon after, the signal came to take that name — The Wow!

Ehman couldn’t help but write “Wow!” next to it on the printout.
| Photo Credit:
Wikimedia Commons

The Wow!

WHEN? August 15, 1977

FAST AND FURIOUS! The signal lasted 72 seconds.

Record of the signal intensity – 6EQUJ5, most intense

Never again

Narrowband, unlike broadband signals, occupy a narrow range of frequencies. The Wow! signal was an extremely narrowband signal with a frequency range of 1420 MHz and it had come from the direction of constellation Sagittarius. Both Ehman and the entire team monitored the same celestial area from where the signal came but no luck. No other signal wowed like the Wow!

Since its discovery, many theories have come up regarding its origin. The culprit has been linked to alien civilisation, some human interference, and even comets. Today, the astronomy establishment has largely drifted away from associating the ‘Wow!’ signal to a message from the aliens. Yet the signal is still alien to us. The latest theory reasons that it is due to a Magnetar (a rare type of neutron star with powerful magnetic energy) and cold hydrogen cloud interaction.