back to article Earth bathed in high-energy radiation from colossal mystery blast

Sometime between 1,237 and 1,238 years ago, the earth was inundated by a massive blast of high-energy radiation greater than any known to have occurred either before or since – but no one knows its source. This startling fact was uncovered by tree-ring analysis – the same technique that has proved so useful to climate …


This topic is closed for new posts.
  1. Denarius Silver badge
    Thumb Up

    maybe both ?

    Sign in sky maybe was a large comet that later hit a large sunspot causing a bigger than usual CME ? To affect any event on sun a comet would have to be big and very fast, perhaps from outside solar system.

    1. Anonymous Coward
      Anonymous Coward

      We are still here so it wasn't that bad was it?

  2. Martin 71 Silver badge

    Must have been God

    He moves in mysterious waves ™

  3. Shannon Jacobs

    How widespread was the effect?

    I didn't see anything in the article about where it was detected. For the entire earth, or primarily in the northern hemisphere. Could they possibly even detect a flash event that affected just one side of the planet for a few hours?

    1. WatAWorld

      Re: How widespread was the effect?

      "... Here we report 14C measurements in annual rings of Japanese cedar trees from ad 750 to ad 820 ..."

      "... When averaged over 10 years, the data are consistent with the decadal IntCal 14C data from North American and European trees ..."

    2. ElReg!comments!Pierre

      Re: How widespread was the effect?

      Given the way 14C is produced and its half-life, it would be have been extremely surprising if it had been a localized observation. Actually it would have been a strong indication of an experimental error.

  4. Don Jefe
    Thumb Up


    This is the kind of story I expect from El Reg! No agenda, no bias, just a good write up of something cool.

    1. Thing

      Re: Yay

      Apparently someone likes a biased agenda.

      1. Destroy All Monsters Silver badge

        Re: Yay

        This article is racist against gamma ray bursts and casts aspersion on people who see flaming crucifixes floating over dead saints' resting places at sunset!

        1. Thing

          Re: Yay

          'people who see flaming crucifixes floating over dead saints' resting places'

          So now I'm thinking it was an early Black Sabbath concert. How old is Ozzy?

          1. Zombie Womble

            Re: Yay

            "How old is Ozzy?"

            Considering his years of alcohol and drug abuse, a lot older than he should be.

            1. Peter Mc Aulay

              Re: Yay

              Certainly he is well preserved.

  5. Long John Brass

    Alcubierre drive signature?

    Perhaps the aliens from life of Brian came back :)

  6. MacroRodent Silver badge
    Black Helicopters

    Odd to have gone unnoticed

    Both radiocarbon dating and tree ring analysis have been in use for decades. Odd that nobody noticed this before. And shouldn't this seriously throw off radiocarbon dates, which assume that C-14 is produced at in the atmosphere at a constant rate?

    1. WatAWorld

      Re: Odd to have gone unnoticed

      The way I read this

      it might be because they normally look at 5 and 10 year averages of carbon-14 in tree rings, and because the bump was only 1%.

    2. Dave Bell

      Re: Odd to have gone unnoticed

      Radiocarbon dates are always a little odd. As we got better information on the half-life, and better instruments, the dates have shifted. There is always some doubt about the relationship between radiocarbon years and calendar years. And we know that the balance between C13 and C14 shifts: all those fossil fuels are effectively C14-free.

      With the half-life of C14, everything since this event is more radioactive. And the chances are we already know that. A sample which is 7000 years old in radiocarbon years has a caibrated age a thousand years different. What really makes this event remarkable is that the scientists have found a year for it, and no apparent explanation from other sources.

      It isn't going to wreck archaeology

  7. Antoine Dubuc

    Where's the sampling coming from?

    World wide ... mm.

    How many places did they sampled to establish it was worldwide?

  8. Resound

    hitsorical record

    The Anglo-saxon chronicle had something:

    "A.D. 774. This year the Northumbrians banished their king,

    Alred, from York at Easter-tide; and chose Ethelred, the son of

    Mull, for their lord, who reigned four winters. This year also

    appeared in the heavens a red crucifix, after sunset; the

    Mercians and the men of Kent fought at Otford; and wonderful

    serpents were seen in the land of the South-Saxons."

    I wonder what they saw that they interpreted as a "red crucifix". I don't have the original text handy, only a translation.

    1. frank ly

      Re: hitsorical record

      I was about to pour scorn on your source because of "... the Mericans and the men of Kent ...", then I realised that I wasn't reading it properly.

      1. Roger Varley

        Re: hitsorical record

        Damn you sir. Just hope no one from Hollywood saw that otherwise there'll be a film next year. And the Mericans will win!

    2. Tom 7 Silver badge

      Re: hitsorical record

      A planetary nebula could easily be mistaken for a crucifix so I guess a nearby one would easily cover all the requirements. We just need to find the culprit.

      Anyone got any Chinese manuscripts from 774?

      1. Michael H.F. Wilkinson Silver badge

        Re: hitsorical record

        "A planetary nebula could easily be mistaken for a crucifix so I guess a nearby one would easily cover all the requirements. We just need to find the culprit."

        Not the planetary nebulae I know. Besides, they are not large enough to be resolved by the naked eye. Planetary nebulae are not supernova remnants, but form when a star roughly the size of the sun blasts off its outer layers. However, let us not forget that the 1054 supernova was seen in the east, but not by western observers (too busy bashing each other's brains in ?). I do not know of a nearby SN-remnant which could be a candidate. A gamma-ray burst may be the culprit, as others have noted.

        As this event is not so much impossible, but very, very improbable, I suggest the Heart of Gold is to blame

        1. Tom 7 Silver badge

          Re: hitsorical record

          NGC 6537 looks very like a cross - and many other planetary nebula exhibit the hourglass appearance that could be interpreted as a cross. The helix nebula is the size of the full moon and 2.5 light years across and may be a candidate - not sure how fast its expanding!

          A nearby one may have dispersed by now, or possibly have blown itself away with a greater explosion later on - maybe the crab nebula was planetary before it went supernova?

          1. Michael H.F. Wilkinson Silver badge

            Re: hitsorical record

            "NGC 6537 looks very like a cross - and many other planetary nebula exhibit the hourglass appearance that could be interpreted as a cross. The helix nebula is the size of the full moon and 2.5 light years across and may be a candidate - not sure how fast its expanding!

            A nearby one may have dispersed by now, or possibly have blown itself away with a greater explosion later on - maybe the crab nebula was planetary before it went supernova?"

            The Red Spider (NGC 6537) is pretty unique in shape, and at 1.5 arcminutes is not very big (and would have been smaller in the past). The hourglass-type side-on nebulae like the Dumbbell are not that cruciform, and though the Helix is the size of the full moon, it is very difficult to spot, even through my 8" scope, as its surface brightness is very low. This is a key problem: high surface brightness planetaries are small, one big enough to resolve by eye have very low surface brightness.

            If the white dwarf at the centre of a planetary is part of a binary (spotted one such system last year), it could go supernova (Type Ia), otherwise this is unlikely (not enough mass). There is no indication that the Crab pulsar is part of a binary, I think. There may be a supernova remnant as yet undiscovered, of course. Supernovae embedded in a star forming region could generate strange light echoes on the surrounding dust and gas.

            Finally, the "red crucifix" in the sky may have been atmospheric, rather than deep sky. A curious illumination of clouds after sunset, noctilucent clouds in a strange formation, auroras, or a bright meteor which exploded (and form cruciform patterns). And finally, if your king or local lord had stated he saw a red cross in the sky (after imbibing some bad mead, maybe) stating you could not see it might be a terminal career move ;-)

          2. Anonymous Coward
            Anonymous Coward

            Re: hitsorical record

            The crab nebular is already recorded with the date it went "up" in Chinese records AFAIK. There are quite a few cross shape nebular or novas that have been photographed. I can't remember if it's the angle or due to rotation/double star systems that does it, but it's quite common.

    3. Phil O'Sophical Silver badge

      Re: hitsorical record

      > I wonder what they saw that they interpreted as a "red crucifix". I don't have the original text handy, only a translation.

      Best I can find is this, although this is from 775:

      Her oþiewde read Cristesmęl on hefenum æfter sunnan setlgonge;

      1. Resound

        Re: hitsorical record

        Well that says the same thing and places it actually in the year mentioned in the article rather than the year before. It also more firmly ties the phrase "after sunset" to the red crucifix. Win!

    4. Anonymous John

      Re: I wonder what they saw that they interpreted as a "red crucifix"

      And the "wonderful serpents" in Sussex? Can we rely on them? The surviving Anglo-Saxon Chronicles are copies written well after 774AD as I recall.

      1. Graham Dawson Silver badge

        Re: I wonder what they saw that they interpreted as a "red crucifix"

        A "red crucifix" and "wonderful serpents" are both very good descriptions of highly active Aurora Borealis, which form all sorts of marvellous shapes. If they're strong enough you'll begin to see coherent plasma formations taking on the form of pillars, crosses, humanoid figures, chalices and all sorts of fancy things. Serpents, which were traditionally sinuous, flying creatures and not necessarily snakes, would be fairly run of the mill.

        A large CME impacting earth would generate very strong, very southerly aurora.

        Additional evidence: the magnetic north pole was much closer to Europe in the 700s and 800s AD (it's moved quite a bit since then) which means that aurora would be more southerly in Europe to begin with, which would explain the serpents - bright glowing, snaking shapes in the sky would be seen as serpents and the flying, dragon-like "worm" and might even have been related back to the norse mythology of Jormungand.

        So the question becomes, was that CME powerful enough to generate more coherent shapes? If it were at the level of the Carrington Event (look it up) then it could well have been responsible for both the sky sightings and the C14 increase.

        1. Armando 123

          Re: I wonder what they saw that they interpreted as a "red crucifix"

          Graham, you are probably right; the aurora borealis would cover the facts and explain the descriptions. That would make high levels of solar activity the likely (though not definite) cause.

          Then again, I seem to recall that the years in the ASC cannot always be taken literally, as events and years were made to fit a pattern. The order is probably valid, but the exact years might not be reliable in all cases. I read that years ago, though, so maybe they have been determined to be reliable.

          1. Resound

            Re: I wonder what they saw that they interpreted as a "red crucifix"

            They can be a trifle sketchy. I seem to recall that they started as annotations to Easter tables which were set up to calculate when Easter would fall in a given year. There were a couple of ways that these could be out; again, I'll have to try to remember to look at this when I get home rather than at work. At least this post-dates the Synod of Whitby :)

            1. Nigel 11

              Re: Historical record

              If it was something naked-eye visible and of duration >24 hours, it would have been seen globally and recorded by quite a few civilisations more advanced than the Europeans at that date. China, for example.

              Unless, possibly, it was in the Southern hemisphere near the (celestial) South pole. Could that have escaped notice?

              1. Michael H.F. Wilkinson Silver badge

                Re: Historical record

                Good point about the southern hemisphere.

    5. Local Group

      Re: hitsorical (sic) record

      This must be Ethelred the Ready because Ethelred the Unready doesn't appear until the first decade of the first millenium.

  9. Right In The Balls

    I'm wondering if there was any record of any drastic temperature changes after this intense radiation for subsequent years.

    1. Anonymous Coward
      Anonymous Coward


      The event will probably only have lasted for a short period of time during the year (days or perhaps a week or two). This is not long enough to have any noticeable impact on climate.

      If you are thinking of Svenmark's Cloud Theory then a couple of cloudier days during a year would be lost in the noise and natural variability of weather.

      Also there aren't any proxies with a high enough resolution and/or accuracy to pick out an individual years temperature.

    2. itzman

      I wonder too.

      Although a 1% jump doesn't sound so massive really.

      And of course since its creating carbon from nitrogen.. which would rapidly oxidise to CO2... ho hum.

  10. Duncan Macdonald Silver badge

    Gamma ray burst ?

    A gamma ray burst from the far side of the Milky Way could have done the job. As a GRB only lasts seconds, if it hit the day side of the earth it could have been completely missed by human observers.

    (A nearby GRB would have been lethal but from the far side of the galaxy and with the dust and gas in the way the biological effects would have been minor.)

    1. Nigel 11

      Re: Gamma ray burst ?

      Would have had to have been a very small one. we don't know enough about GRBs to know if a small one is possible. A regular-sized one, of the sort we observe from cosmologically distant galaxies, would sterlilize the entire galaxy within which it occurred. The biosphere-killing mechanism is atmospheric ionisation, leading to the creation of huge amounts of Nitrogen Oxides, followed by deadly acid rain and ocean acidification.

      A GRB in Andromeda?

  11. BristolBachelor Gold badge

    solar origin

    The statement that if it were of solar origin, then aurora would've been commented on, or it would've done serious damage to the ozone layer assumes a CME type event lasting at most a few days. However, the growth took place over a year, so perhaps a slower, longer lived event could've done it without having to have killed everything, or make people think that they were at a nightclub?

    It seems to me that we don't fully understand the processes in the sun (hence the questions about the recent solar minimum, and the glut of solar science instuments being launched like SOLO - yay)

  12. VinceH

    We were being scanned by a race of alien patent lawyers, to see if we had anything they could sue us for.

    1. honkhonk34

      Let's hope they never come back.

      I'm sure they will hold the meta-patent on the entire patent system we use.

  13. KitN

    Terrestrial origin

    What about an event on Earth rather than in space?

    During the brief era of nuclear bomb testing, we raised the C-14 level massively (see ). I'm not saying someone detonated a nuke in 774 - though a mushroom cloud might well have been interpreted as a "red crucifix" at that time:) - but a terrestrial event would not need to be of cosmic scale energy to affect our atmosphere.

    If it were an Earth event, the effect would vary a lot more over area & time than if it bathed the earth uniformly from space, and that would show up as differing spikes in the C-14 in tree rings - one way to test the idea.

    Another point though: if most ring surveys are averaged over 5-10 years, might there not be other single year spikes we aren't aware of? Maybe they are common, in which case this data wouldn't indicate an anomaly at all.

    1. Christoph

      Re: Terrestrial origin

      It's pretty obvious what it was - that Merlin chappie was messing about with a new spell and some Uranium, and didn't realise just how big the result was going to be.

      1. Destroy All Monsters Silver badge

        Re: Terrestrial origin

        Arthur: What manner of man are you that can summon up fire without flint or tinder?

        Tim: I... am an enchanter.

        Arthur: By what name are you known?

        Tim: There are some who call me... 'Tim'...?

        Arthur: ...greetings, Tim the Enchanter.

      2. Euripides Pants

        Re: Terrestrial origin

        Damn wizards!

        1. Nigel 11

          Re: Terrestrial origin

          If so, one would expect many other radio-isotopes to be anomalous. I'd rather expect someone to have noticed the evidence of atmospheric H-bomb testing during the dark ages in (say) skeletons, but I guess it might be masked by the evidence of atmospheric H-bomb testing during the cold war.

    2. Anonymous Coward
      Anonymous Coward

      Re: Terrestrial origin

      I wonder what the chance is of natural materials going nuclear themselves? I've heard of a few "hot springs" powered by radioactive rocks, but nothing close to going critical. :P

      1. Mike Richards Silver badge

        Re: Terrestrial origin

        Chain reactions can't happen in natural uranium on Earth as the level of fissile U235 is too low to sustain the reaction. Well it is now - if you go back in time, the proportion of U235 in uranium rises to a point that self-sustaining reactions could occur. So far one site is known where this happened, it was discovered at Oklo, Gabon in 1972 by French geologists mapping a uranium deposit. They discovered the level of U235 at Oklo was even lower than normal. About 1.7 billion years ago, the ore would have been about 3% U235 (compared to about 0.7% today), water circulating through a uranium ore acted as a natural moderator allowing a self-sustaining chain reaction to run at very low power for hundreds of thousands of years.

        Personally I go with the idea that this C14 spike was caused by Camelot's nuclear testing programme.

  14. Anonymous Coward
    Anonymous Coward

    Did it affect the underside of the earth as well as its flat surface?

  15. Joe Gurman

    Erm, magnetic charges?

    Unless you've managed to find the elusive magnetic monopole (and this contradict one of Maxwell's equations), there's no such thing as "magnetic charge." Coronal mass ejections can, however, accelerate electrically charged particles by bottling them up in a shock if the mass ejections are traveling fast enough.

    1. Destroy All Monsters Silver badge

      Re: Erm, magnetic charges?

      But really, no-one cares about Maxwell's equations because of course they are classical approximations of "some other thing" (there is the photon quantum field, but getting Maxwell equations out of its description takes some serious operator algebra). So Maxwell's equations do not say much about the existence or not of magnetic monopoles.

    2. Anonymous Coward
      Anonymous Coward

      Re: Erm, magnetic charges?

      "...(and this contradict one of Maxwell's equations)"

      Not contradict, just extend. Maxwell derived his equations from observation, and since he never observed a monopole, he set the divergence of a magnetic field to be zero. Since he HAD observed electric charges, he set the divergence of the electric field to be proportional to the charge in the enclosed volume

      All that observing a monopole would do to Maxwell's equations would be to cause divB to be equal to the magnetic charge in the enclosed area.

      1. Nigel 11

        Re: Erm, magnetic charges?

        I've always thought that Maxwell's equiations should be written with a term for the density of magnetic monopoles. They are far more symmetrical and elegant that way. Add a statement that magnetic monopoles have never been observed, and that for all everyday purposes this density is everywhere equal to zero, leading to the common formulation of the equations.

        On the other hand, cosmologically, in a universe having 4-spherical topology, there must be at least one monopole somewhere, or else magnetic fields could not exist at all.

  16. Anonymous Coward

    Standard procedure

    Nothing unusual it was an asari exploration vessel discharging its drive core....

  17. Anonymous Coward
    Anonymous Coward

    Crucifix and serpents

    Yes, the crucifix could be interpreted from an explosion and the "wonderful serpents were seen in the land of the South-Saxons" could easily have been aurora's from the blast. "Wonderful serpents" indeed. Not terrible, but wonderful, which could mean pleasing which aurora's certainly are to the eye and mind. I have been close enough to hear them hiss and for ancient man they must have been a wonderful sight to behold and the edges could seem like "serpents" if I had no other explanation for them....

  18. Isn't it obvious?

    Hidden supernova?

    I've wondered about what the observable effects would be of a supernova that's (mostly) obscured by a cold nebula (like the CoalSack nebula); might that selectively block most of the visible light, while letting other sufficiently energetic wavelengths and/or particles through? Or diffuse the light sufficiently for it to be lost in the general galactic glow?

  19. Sureo


    775 was the year the earth was scanned by the Borg and found not worth assimilating.

  20. sisk

    I for one welcome our not so new mysterious radioactive overlords.

  21. Anonymous Coward
    Anonymous Coward

    It is part of the time machine paradox

    Every time someone creates one of those infernal time machine contraptions, they just can't leave well enough alone!

    No, they just have to travel back in time, to rape plunder and pillage, or try to make their fortune, or just to do the dead cat curiosity thing (this isn't Schroedinger's cat here, this is your time machine is a dead cat idea if you travel back in time. Or try to. You might even become dust to dustless. Time abhors a traveler moving at negative velocities).

    They kill off dinosaurs by accidentally timeporting their asteroid base to the Yucatan, they contaminate the primordiam with all one handedness of dimer, and now THIS. I mean really, don't these guys get it? You can't go back and change things the way you want. But Noooooo, Jack has to push the "go" button and whammo, nuke in Siberia and mystery C14 splattered all over the world. Archeologists will probably decide the hole, when they inevitably find it, was cause by an asteroid (if it quacks... yeah, no imagination those peer reviewers, never let the time machine hypothesis see the light of day! It has to be an asteroid, or unusual uranium formation that went critical, or even Mikhockski in his yurt building a home made thermonuclear device but never a time machine, no siree sir!).

    So you Reg readers with delusions of time transport and making a killing the stock market, just remember, Mother Nature doesn't like time machines. It gives her gas pains. And you really DON'T want Mom to have those kinds of gas pains when you are traveling!

    1. The Aussie Paradox

      Re: It is part of the time machine paradox

      Sir, Your ideas are intriguing to me and I wish to subscribe to your newsletter.

  22. Jean-Luc


    It was the birth of the great-great-great....(43x) grand-father of Kim Jong Il. The skies wept at the sight of his magnificence.

    Wait till the current fat boy has an offspring. Big spike in C14 coming!

  23. This post has been deleted by its author

  24. Local Group

    Lord of the Tree Rings

    If you want to know who we are,

    We are Gentlemen of Japan

    Selling many camera and car

    And 52" plasma tv and van.


    We looked at tree rings back in 775

    And saw lots of carbon fourteen.

    That year most everyone did survive,

    Thanks to a weak force still unseen.

This topic is closed for new posts.

Biting the hand that feeds IT © 1998–2021