One of the greatest philosophical as well as practical questions of our time is. “Are we alone in the Universe?” I think there are countless lifeforms in our Milky Way galaxy as well as in the billions of other galaxies. Whether, at any particular time, how many would be at least as intelligent as us or more advanced and I think the number will drop massively. But since it appears at the moment that most stars we have investigated have planets orbiting them, the number should still be large.
For us to answer this question, we have aimed radio telescopes at areas of the sky and listened out for any signals that might indicate they came from an artificial source. The SETE programme is set up for this purpose alone. SETI stands for Search for Extraterrestrial Intelligence. As yet, they have not discovered anything that indicates other life.
However, there was one occasion when the world woke up and thought that we had found an alien signal. It happened on the 15th of August 1977 when the Big Ear radio telescope at Ohio State University picked up a signal. It only lasted for 72 seconds but bore the hallmarks of not coming from a natural source. It was thirty times louder than the background noise they were used to. The source is believed to have originated within the constellation of Sagittarius.
It was and is known as the “WOW Signal.” This is because when the astronomer watching the data come in, Jerry Ehman, wrote on the printout, the word “WOW.” For those who would like the technical details, it was found on the electromagnetic frequency band of 1420.4056 megahertz.
What is interesting is that this is the frequency given out by hydrogen, the most numerous element in the Universe. Some scientists believe that if you were to send a radio signal out into the galaxy, a narrowband signal close to the hydrogen band is a logical thing to do. To this day, we cannot be certain if this is alien or even just a reflection of a radio source from our planet as some think.
Have we ever sent signals out into space which could be picked up by alien civilisations? The answer is a resounding yes. This is because every radio or television transmission heads out into space. Just think of that. An alien astronomer is quietly sitting there watching for any signs of alien life and one of our weirder TV shows suddenly appears! At least they will not believe it comes from an intelligent life form!
John Pullen 