I thought it might be a good time to revisit the big question on so many minds for so many years. Are we alone?
Many wonder why, in a galaxy supposedly teeming with life and after searching the cosmos for over 50 years with increasingly powerful radio telescopes, have we not heard a thing? Is it because the only aliens we will ever find are currently on our summer movie screens? Since the search began in earnest by Frank Drake in 1960, there have been a few candidate radio signals that have initially increased the heart rates of SETI scientists, but then after careful scrutiny turned out to have very mundane explanations.
All except for one.
In 1977, while working on a SETI project at Ohio State University, Jerry Ehman discovered a signal that had been received from the university’s Big Ear Radio Telescope that was so startling he circled the numbers on the printout and wrote, “Wow!” The intensity of the signal was 30 times more powerful than the normal background radiation and could almost certainly be construed as a cosmic hello. This has become known as the famous Wow signal.
When scientists first began the search for extraterrestrials using radio telescopes, they came up with a set of criteria that would indicate if a signal could be of extraterrestrial origin: 1. Accounting for the Earth’s rotation using a fixed telescope the signal would have to show a gradual peaking and then gradual decrease. 2. It should be in a narrow band and very concentrated. 3. The best place to look would be in a frequency where interstellar hydrogen (the most common element in the galaxy) glows brightest. 4. It should repeat so it can be studied and verified by other installations around the world. The Wow signal fit all the criteria perfectly. Looking exactly like a signal from another world would look like. Except for one thing …
It never repeated.
For over 35 years scientists have tried to reaquire the signal from that part of the sky and also tried to find any reasonable, terrestrial explanation for what may have caused it. They came up short on both accounts. So to this day it is still referred to as a mystery, but one with not enough weight behind it to dissuade scientists from saying that after 50 years SETI has failed to come up with anything. Funds for SETI research are getting harder to come by, forcing scientific icons like Jill Tarter to quit her job to cut costs and raise additional funds to help the struggling endeavor.
Maybe it’s time to finally give the Wow signal the proper respect it deserves. Robert Gray has just published an entire book devoted to the subject. It certainly fits the profile of an extraterrestrial signal. It just doesn’t repeat—a word that should have never been a part of SETI’s criteria for knocking a signal out of contention. Repetition would be nice, but remember our largest radio telescope in Arecibo Puerto Rico in 1974 beamed out a powerful signal into the cosmos … and never repeated! So there you go. You don’t need repetition as a life indicator. Maybe what we received back in 1977 was similar to a kind of lighthouse beacon, and we were just lucky enough to get caught in a piece of it as it swept by. Or perhaps by accident we intercepted a portion of a ship-to-ship transmission between two spacecraft before they moved on. It fits the profile and has resisted all attempts to be disproven. People are convicted in courts all the time on far less circumstantial evidence.
But is it proof? Of course not.
There was probably never going to be any definitive proof anyway. At least not for a very long time. Short of aliens landing on the White House lawn, shouting, “Here we are,” or sending us the kind of elaborate message portrayed in the movie “Contact,” there would always be only degrees of educated guesses by some very smart people saying things like, “I believe we have finally made contact” or “We may have finally received a signal” … or something like that.
Jill Tarter says the search for extraterrestrials is in its infancy and by comparison would be like taking a glass, filling it with water from the ocean, and upon seeing no fish declaring none exist.
There are other things to consider as well. In 20 years or so we will be able to image extraterrestrial planets directly. Imagine what beings thousands of years or more advanced than us are able to do. I would say it’s a good bet they have been aware of us for quite some time. Noted Physicist Paul Davies thinks its time to broaden the scope of SETI to include looking at additional frequencies of the radio spectrum, including optical. He also theorizes that given the likelihood that aliens have been around a lot longer than us, we should also do extensive searches of our Moon, the solar system, and even the Earth itself for possible evidence of their passing this way before.
In an age where we can delist a planet like Pluto, I believe it’s finally time to elevate the Wow signal’s status from the dark realm of a one-off mystery to the first good possibility that we have already received an alien signal! Not proof, but enough to kickstart renewed interest and give SETI the help they need so we don’t have to wait another 50 years before we receive our second potential extraterrestrial contact.
This article originally appeared on the Society for Planetary Defense website, which can be viewed by clicking here: SETI
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We will find evidence of microbial life well before intelligent life and that will happen soon. Someone once stated that “divine separation” prevents us from ever making any contact with alien intelligent life. I reject that notion. SETI is indeed in its “infancy” in the cosmological time scale. But in time and with the developments in technology, we will make such a discovery that will forever change our understanding of the cosmos.
I think you’re right on that. With any luck we will find microbial life within our solar system.
For SETI, so much depends on where we are looking, and especially when other intelligent life is broadcasting (and how far away).