You would think that an explosion packing a punch of nearly 10,000 atomic bombs would raise a few eyebrows - or at least burn a few of them off. Yet, there are no historical records of strange or catastrophic events happening in 775 AD, when scientists say an unexplainable blast of high-intensity radiation hit the Earth with enough energy to dig the graves for over a million potential casualties.

That is a considerable amount of devastation to not make its way into the history books considering approximately 350 million people were inhabiting the planet at that time. Of course, we understand what it’s like to not have a pen handy.

Last year, scientists discovered significant evidence of a massive explosion while studying the levels of radioactive carbon contained inside the growth rings of some of the oldest trees in the world. Essentially, what they found was higher levels of carbon-14 (made when energy particles enter the atmosphere of the Earth and crash into nitrogen atoms) in the 775 AD growth rings than any other documented time in 3,000 years.

Initially, scientists believed that this spike in carbon-14 was caused by a solar flare or the explosion of a nearby star. However, both hypotheses were dismissed due to such events having the capacity to produce an onslaught of mass extinction, or at bare minimum, a magnificent electric sky brought on by the northern lights. Again, nothing out of the ordinary was documented.

Yet, researchers from Germany recently concluded that the high carbon phenomenon is likely due to a fierce gamma ray caused by two colliding neutron stars. And while this occurrence would have shaken the atmosphere with a mighty furor, it could have easily been missed due to it only being visible from our planet for right around a day. Think Hiroshima on steroids with the longevity of a 24-hour flu virus.