Sun unleashes a SECOND Monster X class solar flare – strongest in a decade

Earlier this week, on Sept 4th, active sunspot AR2673 hurled a CME toward Earth. Now a second monster sized flare has been released from the same region.

On Sept. 6th at 1202 UT, sunspot AR2673 unleashed a major X9.3-class solar flare–the strongest solar flare in more than a decade. X-rays and UV radiation from the blast ionized the top of Earth’s atmosphere, causing a strong shortwave radio blackout over Europe, Africa and the Atlantic Ocean (blackout map). The explosion also produced a CME. However, available coronagraph images are not yet sufficient to determine whether or not the CME is Earth-directed.

According to the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center (SWPC). The last X9 flare occurred in 2006 (coming in at X9.0).

A Radiation Storm Warning for 10 MeV protons greater or equal to 10 pfu (S1 or higher) is in effect until 0400 UTC on 7 Sept.

Above: The extreme UV flash from today’s X9-class flare. Credit: Solar Dynamics Observatory

Added: NASA just released this short animation, it appears that the flare was directed away from Earth. Thank the heavens.


The sun today:

The sunspot responsible for this morning’s flares, active region 2673, is the smaller of two massive spots on the sun’s surface, at only seven Earths wide by nine Earths tall, according to astrophysicist Karl Battams as shown in the Tweet below.

h/t/ to Dr. Leif Svalgaard


From NASA’s

This is a decade-class flare. A list of the most powerful solar flares recorded since 1976 ranks today’s flare at #14, tied with a similar explosion in 1990. Compared to the iconic Carrington Event of 1859, or even the more recent Halloween storms of 2003, this event is relatively mild. Modern power grids, telecommunications, and other sun sensitive technologies should weather the storm with little difficulty.

84 thoughts on “Sun unleashes a SECOND Monster X class solar flare – strongest in a decade

  1. John Cook must be bursting with opinions on stories like this, with his decade-old BSc in solar physics.
    Unfortunately we all know “It’s Not The Sun!” (as the SkS boyz say in their inimitably monosyllabic way) so he can’t comment, lest he give succor to Top Ten climate myffs.

    • Although the ISS is within Earth’s magnetic protective fields and receives some protections from these, there exist no good places really. They shelter within the most shielded modules and try to rotate the entire ISS to allow the solar arrays to act as shields as well.
      Any exposure will be measured.
      These events are watched closely for just such procedures. Bigger issues arise when traveling outside of Earth’s magnetic belts such as in lunar trips where the astronauts are exposed. We see the flares in a matter of minutes, but It can take days for a slower moving CME to reach earth. Radiation shielding is HEAVY so during the Apollo days they timed launches for low activity periods, crossed their fingers and hoped. BTW the radiation poisoning doesn’t kill immediately.

      • Actually there is a good bit of research on radiation shielding because we don’t want to remain earthbound. Several good candidates for materials exist. Interestingly enough polyethylene works rather well, but you need a rather thick panel so the weight goes up. The best candidate by far is water. The idea is to locate the tanks around the periphery of the crew module in such a way as to create a safe cubby hole to crawl into. The water will never be expended as it will be continually recycled.

      • Wouldn’t the accompanying proton storm ionize the hull of the ISS, and protect the occupants from protons?

      • @rocketscientist – Amuses me some when the oldest ideas are sometimes still the best solutions. Water tanks to stop the particles (many of which are going to be secondaries from your ship’s outer shell), and an inner dense metal cladding to stop any remaining X and gamma photons.
        I remember reading this solution first in Heinlein’s Podkayne of Mars (early 1960s) – but I think it was Willy Ley who first floated it, many years before that was written.

      • Apollo — they crossed their fingers and hoped. The lunar flights ran from December ’68 to December ’72, just past the peak of Solar Cycle 20 (maximum was observed November ’68). With a mission lasting 10 days, it would be hard to know the activity would stay low, and the probability wasn’t good.

  2. So just about the time Irma hits the keys Earth will see another CME? Hope they don’t rely on short wave radio for evacuation alerts.

      • after brief conversation yesterday, I looked up website for the ‘Florida Keys Wild Bird Rehabilitation Center’ and noticed that many birds are kept confined in large enough wooden enclosures but which may not survive even Cat 1 hurricane. I suppose not much can be done.
        Hope you ready to evacuate if need be, best of luck.

      • Yes. Not too happy about that. But ECMWF ensemble has it following very the Matthew track from last year. Most we saw was about 45 mph. We have been ordered to clear the balconies by noon tomorrow. Matthews drill. Whether we evacuate we will make Friday am. Gives us 24 hours.

      • Cerescokid, thanks. We are fully prepared if stay, and fully prepared if decide Friday am to leave. All depends on the cone of uncertainty for the eye less than 48 hours out, when the uncertainty is small. Media including Weather Channel is doing a lot of hyping given the present huge uncertainty. ‘If it bleeds, it leads’ truism. Hurricane winds in this ‘big’ storm extend out 50-70 miles from eyewall. So if we are predicted to be with fairly high certainty just 30 miles from eyewall, we will see nothing over Cat 2 and will stay put. Physics law of conservation of angular momentum applies to figure skaters and to hurricanes.
        We are already under ‘mandatory evacuation’ east of US 1 in Fort Lauderdale. Not a joke for all the old one story ranch style cinder block homes that could suffer storm surge and also do not have now mandatory steel roof ties. A joke for us directly on the Atlantic beach but up 12 stories in a post Andrew code reinforced concrete building. IF necessary and we stay, we will move one car away from its exterior third floor parking spot to avoid possible flying debris damage, and move the other to some other interior third floor parking spot from the ground floor to avoid possible storm surge. Building is only 1/3 occupied in the crazy summer heat and humidity here right now. So plenty of open parking spaces to co-opt.

      • ristvan September 6, 2017 at 2:23 pm
        Not a joke for all the old one story ranch style cinder block homes that could suffer storm surge and also do not have now mandatory steel roof ties.

        The experience with Hurricane Andrew was that the houses built in the 50s and 60s held up well. link
        The houses that were destroyed were engineered so precisely that any mistake by a workman would fatally weaken them. My ‘favorite’ failure mechanism involved rain getting up under the shingles because of a missing staple or something. The OSB roof cladding would swell and this would cause the staples to cut through the shingles. The shingles would leave, followed shortly thereafter by part of the roof deck. The wind would get in and that would be it for the house.

      • Commie,
        You’re right. Roofs with real nails mostly survived. Those which failed were built with “nail” guns, which shot in too few staples. You need many staples to equal a real, good, old-fashioned roofing nail. And not enough had been shot in the ’70s and ’80s.
        Not just water but wind.

        • People shooting too few nails/staples does occur. The real cause of shingles coming off is people running the pressure too high on nail/staple guns and the nails/staples breaking the surface of the shingle. They are, in fact paper. Asphalt impregnated fiber(that just don’t even sound right on so many levels) that can be torn rather easily. One of the reasons I really push for people to go metal!

      • 2hotel9 September 6, 2017 at 6:16 pm
        … One of the reasons I really push for people to go metal!

        If I were buying a new house and could pick one upgrade, it would be a nice looking metal roof.

        • And there are so many options! You can get a metal roof that looks like shingles, cedar shakes or slate(I really like the slate-metal, it has very tight joinings with an adhesive layer inside the groove) and you can opt to use more screws with just a slight increase in price. Wow. Got to talk to our local supplier and see if I can get a % commission for posting stuff like this! 😉

    • Wasn’t it hurricane Andrew that released the pythons and other non-native exotic snakes into the Everglades? As I recall a US customs detention center where they housed confiscated reptiles was flattened and all the critters escaped into welcoming habitats.
      Seems they haven’t learned that lesson yet.

      • Not clear. That is one explanation. For sure, we now have an Everglades burmese python problem. I favor an open python hunting season and up priced Texas python cowboy boots. Big northern US game hunter, no desire to hunt alligators (too easy) or pythons (too hard).

  3. Leif,
    Would this flare show through my filtered 8″ sct scope or telephoto lense, f8.3, in regular old visible light?

      • @JimG1
        Great shot. It is fascinating to compare to the ones that we got at the same moment during the eclipse. Sunlight is beginning to sneak around the moon at a spot on the right side as well as the large area in the upper right.
        The dot on the lower left is Mercury.

        • White light flares:
          “The flashes of white light accompanying some solar flares are caused by the sun’s acceleration of electrons to speeds greater than half the speed of light.
          The phenomenon’s new explanation derives from data recorded from a 2006 solar flare. The presence of high-energy X-rays in the same spot that scientists saw visible light tipped them off that some kind of non-thermal process was generating the light.
          “These explosions are particle accelerators,” said Säm Krucker, of the Space Science Laboratories at the University of California, Berkeley. “The whole surprising thing with these flares’ light is that it could simply be heat. But that’s not the case.”
          Solar flares occur when the sun’s magnetic field lines rearrange and reconnect, releasing tremendous amounts of energy. There are different types of flares, which can generate geomagnetic storms of Earth, and only some of them are accompanied by the white light flares. These were first observed in 1859 by astronomer Richard Carrington, but no one really knew how they were produced until the new observations by the Japanese satellite Hinode and the NASA SMEX mission RHESSI.
          Now, it looks as if the extremely powerful electromagnetic fields somehow deliver enormous amounts of energy into particles in the sun’s photosphere. It’s not unlike what humans do at a much, much smaller scale in particle accelerators like the Large Hadron Collider.
          “As opposed to the LHC where you accelerate a few particles, it would be like accelerating the whole building basically,” said Hugh Hudson, also of Berkeley’s Space Science Laboratories, who worked with Krucker.
          Astronomers haven’t figured out how exactly the sun works as a particle accelerator just yet. “It’s being done by electromagnetic effects that are not really understood,” Hudson admitted.”
          Sunquake: unusually strong.

    • Holy smokes Vuk’s. When that first one blew it scared me Within the first CME you could see the first cloud spread out quick and then the second part of the same blast carry out the debris. With a front that big how could it miss?
      Hi Dr. S., your Stanford link above came up Forbidden no access type page.

  4. Displaying my ignorance here:
    How large does a CME have to be to cause large scale power grid damage/failure?

  5. The Sun is being very generous… just in:
    Space Weather Message Code: ALTTP4
    Serial Number: 541
    Issue Time: 2017 Sep 06 1800 UTC
    ALERT: Type IV Radio Emission
    Begin Time: 2017 Sep 06 1733 UTC
    NOAA Space Weather Scale descriptions can be found at
    Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.

  6. most dangerous bit is overflying south Atlantic.
    South Atlantic Magnetic Anomaly: the white spots on this map indicate where electronic equipment on the TOPEX satellite was affected by radiation as it orbited above.
    In similar situations most sensitive bits of equipment can be powered down.
    The International Space Station, orbiting with an inclination of 51.6°, requires extra shielding to deal with this problem. NASA has reported that modern laptops have crashed when Space Shuttle flights passed through the anomaly.

    • No don’t you know that solar flares create storms. Following this I predict that there will be one on Sunday.

    • That’s easy – he backed out of the Paris Accord. Everything bad that has happened since then is the result of that.

  7. Could it be that we haven’t heard anything from Barbuda since the eyewall hit the northern half of that island last night because the island is located in the shortwave blackout area?

    • I was watching that station last night and with a steady wind of 103kts and the wind coming from the north I figured the anemometer was taken out by some debris

  8. A question.
    Do we know what effects such events have on, say, the formation of ozone? Carbon 14, clouds etc.?
    Generally speaking, this layman has only heard of such events effecting radio and power grids.

  9. With major hurricanes a lot of people are left depending on radio, hope this does not give them a secondary screwing along with the one Irma is delivering.
    Been so wrapped up in storm watching I have neglected to do my usual checks on NASA solar observation pages.

  10. CME. Would that be Coronal Mass Ejection?
    For readability, could we have acronyms identified, please.

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