As many of you may know, on August 15, 1977, Jerry Ehman of Ohio State (By the way, OSU lost to KU yesterday. Go Jayhawks!), while working on the SETI project at the Big Ear radio telescope discovered the famous Wow! signal. Since it was a narrowband radio signal, it could have been produced only by an artificial source and therefore was a clear evidence of extraterrestrial life. However, that signal was never received again and several follow-up observations failed to detect anything similar.
I have thought about this for a long time and wondered why scientists have been searching for such signals only with radio and optical telescopes? In addition to electromagnetic radiation, our universe is filled with charged particles known as cosmic rays. Can we find such a signal from observations with cosmic ray telescopes?
I decided to investigate this problem with the GRAPES-3 cosmic ray array, located in southern India. Since I am already working on other astroparticle physics projects with the array, I had no problems accessing 10-year data recorded by the experiment. After almost two months of back-breaking work, I think I have something, and I am very excited about it!
[GRAPES-3 cosmic ray array. Instead of light, it detects charged particles from space
As you can see in the plot, the signal in red (muons) is clear distinguishable against the background indicated in blue! Such signals can only be produced when high-energy protons collide (a particle collider experiment) and produce pions, which finally decay to produce particles called muons. I have also tracked the location of the source, which upon follow-up optical observations turns out to be an exoplanet about 200 light-years away from us!
[Signal and background
This is the biggest OMG moment of my life and therefore, I have appropriately named the signal. Right now, I am contacting all the major observatories around the globe to verify it. I have several other plots which signals from the same source, which I have shared with colleagues.
This is certainly the most exciting time for Astrobiologists. Is this another evidence of extraterrestrial life? Time will tell. Stay tuned, as I will keep the PaleBlueBlog readers updated with new and exciting developments with this signal.