[HN Gopher] Level S4 solar radiation event
       ___________________________________________________________________
        
       Level S4 solar radiation event
        
       https://www.swpc.noaa.gov/products/goes-proton-flux
        
       Author : WorldPeas
       Score  : 594 points
       Date   : 2026-01-19 20:26 UTC (1 days ago)
        
 (HTM) web link (www.swpc.noaa.gov)
 (TXT) w3m dump (www.swpc.noaa.gov)
        
       | uticus wrote:
       | Possible aurora visible through central US tonight
        
       | dschuessler wrote:
       | This page looks like an accessibility nightmare. The entire
       | warning text is an image. There is no transcription present for
       | screen reader users. I did not expect this from a government
       | website.
        
         | delusional wrote:
         | Looking at the aspect ratio (and working in a bank) it's worse
         | than that. That's a powerpoint slide.
        
         | delfinom wrote:
         | Not like someone with poor vision is going to be able to see
         | the aurora borealis that results
         | 
         | /s
        
         | cwillu wrote:
         | https://www.swpc.noaa.gov/communities/aurora-dashboard-exper...
         | is better
        
       | miduil wrote:
       | Nice, you can already see some solar flares in Austria again.
       | 
       | https://www.foto-webcam.eu/webcam/kleinfleisskees/
       | 
       | https://www.foto-webcam.eu/
        
         | qwertox wrote:
         | Oh wow! https://www.foto-
         | webcam.eu/webcam/ederplan/2026/01/20/0000
         | 
         | And up at the top right, left to "Latest" you can skip the time
         | back and forth at 10 minute intervals. And then jump back like
         | 10 images, what a beauty.
         | 
         | You can even see Starlink satellites https://www.foto-
         | webcam.eu/webcam/ederplan/2026/01/19/1820
        
           | irjustin wrote:
           | Possibly the most brilliant are around:
           | 
           | - https://www.foto-webcam.eu/webcam/ederplan/2026/01/19/2230
           | 
           | - https://www.foto-webcam.eu/webcam/ederplan/2026/01/19/2240
           | 
           | Incredible, thanks so much!
        
             | chakintosh wrote:
             | Crazy how many starlink satellite trains can be seen here.
             | I spotted 4 trains, in that one cam
        
               | irjustin wrote:
               | Isn't that just 4 sats and it looks like that because of
               | long exposure?
        
           | jcims wrote:
           | Not to be a buzzkill but I think those are planes. The stars
           | show trails so these must be long exposures, and trails of
           | similar length appear to be going in all different
           | directions, eg: https://www.foto-
           | webcam.eu/webcam/ederplan/2026/01/19/1820
        
         | caseyohara wrote:
         | Those images around 19:00 are amazing. Thanks for sharing.
        
       | zahlman wrote:
       | It seems that the peak was several hours ago, and I haven't
       | observed any effects from it...
        
         | guerrilla wrote:
         | The peak was originally supposed to be 6-7 hours from now...
         | it's still showing KP 8 here though, so I'm not sure what's
         | going on. It could get more intense.
        
       | bartman wrote:
       | We had intense aurora in Berlin, Germany. Green clouds dancing in
       | the sky levels. Started around 22:10 local time or a bit earlier,
       | and at this point there's only a faint red/green glow remaining.
        
         | paulmist wrote:
         | Also seen in the Netherlands!
        
         | rob74 wrote:
         | Yeah, there were auroras even as far south as Munich. Maybe not
         | as intense, but it's the first aurora I ever saw, so I can't
         | really judge...
        
           | ccozan wrote:
           | I am south-west of Munich and with a perfect clear sky I
           | could only see stars, one meteor, and that's it.
        
             | Kyro38 wrote:
             | We also had them in Grenoble, south of France.
        
             | fransje26 wrote:
             | It was visible in the 22:00-23:00 time window. Here in the
             | south west, the sky started turning green around 22:30.
        
         | Tachyooon wrote:
         | Could you see it from the inner city or only closer to the
         | edges?
        
           | bartman wrote:
           | Friends who live in Kreuzberg and Friedrichshain could see it
           | pretty well. I'm a bit further south within Berlin where
           | skies are minimally darker, but between 10pm and 11pm it was
           | so bright that light pollution didn't matter.
           | 
           | Funnily enough, despite having lots of alerts set up it was
           | my mom who texted me from northern Brandenburg as she spotted
           | it after getting an alert from RegenRadar, of all apps...
        
             | Tachyooon wrote:
             | It's amazing to hear it's visible in such a big city. I
             | don't have a good intuition for all the metrics that
             | describe how strong this storm was/is, but when put like
             | this it hits home.
             | 
             | Nice to hear earth weather apps also work great in space
             | haha. I'll keep that in mind when I set up my own
             | notifications. Hopefully I have time to look into it before
             | the next storm hits.
        
             | thrawn0r wrote:
             | Saw it in Fhain as well over Ostkreuz station
        
         | fluxflexer wrote:
         | Just spend an hour outsite (Northern Germany, 01:00 MET).
         | Unfortunately nothing to report, neither visual nor on camera.
         | Maybe I just went to late and missed the show. I hope you habe
         | more luck in Canada and the US!
        
           | jacquesm wrote:
           | It's pretty subtle right now here in NL but I can still see
           | it with the naked eye. Mostly greenish haze that fades in and
           | out.
        
             | CalRobert wrote:
             | ahh I just went outside (south of Utrecht) and saw nothing.
             | Maybe too much light pollution.
        
               | jacquesm wrote:
               | I'm lucky in that I was close to the IJsselmeer.
        
           | madduci wrote:
           | I'm Berlin was around 22-23 o'clock visible
        
         | karim79 wrote:
         | I was just out at a dog park and saw nothing! We have clear
         | skies. I can't believe I missed this.
        
           | danesparza wrote:
           | Next time take a long exposure picture with your phone. You
           | might be able to see it that way.
        
         | TacticalCoder wrote:
         | I tought I was seeing aurora borealis here at 4 am local time
         | in the neighboring Grand Duchy of Luxemburg but it was just
         | visual pollution due to lights from a city.
        
         | madduci wrote:
         | Can confirm, I've seen pink/green glow over Berlin Sky (and
         | pictures as well)
        
         | marc_g wrote:
         | Oh really? Oh no I missed it! Is it going to happen again
         | today?
        
       | ComputerGuru wrote:
       | Do you need long exposure to make it visible with a camera? How
       | does that work in the presence of light pollution?
        
         | thebruce87m wrote:
         | Tonight I could see the colours without the camera but it
         | definitely stands out more with the long exposure of the
         | camera.
         | 
         | Even with lights in the direct line of the shot you you can get
         | good results - presumably the phone is doing HDR to achieve
         | this.
        
         | Macha wrote:
         | Local light pollution normally makes it hard to see with
         | anything short of long exposure, but today it was naked eye
         | visible and regular photos also captured it.
        
       | jjcm wrote:
       | If anyone is interested in what "G4" means in context, here's the
       | scale: https://www.swpc.noaa.gov/noaa-scales-explanation
        
         | xeckr wrote:
         | Looks like we get these for about 60 days for periods lasting
         | 11 years.
        
         | irthomasthomas wrote:
         | We are at kp 8.67. The Carrington event was a kp 9
        
           | ianruh wrote:
           | I am not an expert, but it's worth noting that the kp index
           | has a maximum value of 9. So though the Carrington event had
           | a kp of 9, its intensity on the related (but not capped)
           | HP30/HP60 scale [1] would likely have been higher. [1]
           | https://kp.gfz.de/en/hp30-hp60
        
             | repeekad wrote:
             | Queue Chernobyl documentary clip measuring the radiation as
             | low because that's as high the meter went
        
               | celsoazevedo wrote:
               | 3.6 roentgen. Not great, not terrible!
        
               | qingcharles wrote:
               | *skin sloughs off*
        
               | anonym29 wrote:
               | You didn't see any graphite because it's not there!
        
               | wafflemaker wrote:
               | Everything about these miniseries was wonderful.
               | 
               | Casting (who played who), acting, costumes and
               | scenography (where did they get all these '80 soviet
               | cars), and choice of scenes to film.
               | 
               | I had my hair rising when the guy cleaning roof of a
               | building neighboring the reactor got stuck in deadly
               | radiation zone for 4x the allowed 13 seconds. "You're
               | dead comrade."
        
               | anonymous344 wrote:
               | here, take one o
        
               | wyldfire wrote:
               | Everybody's a diacritic.
        
               | wyldfire wrote:
               | s/queue/cue/
               | 
               | Though I suppose you _could_ also queue it.
        
               | repeekad wrote:
               | Meant the first and people should do the second,
               | Chernobyl on HBO is great.
               | 
               | It's also technically not a documentary but historical
               | drama.
        
               | banku_brougham wrote:
               | kp 9 - not great, not terrible
        
           | echelon wrote:
           | Have we been having these more recently?
           | 
           | I don't ever recall seeing these in the news so frequently.
           | It feels like there are several a year now. A decade ago,
           | never.
           | 
           | And I also never remember seeing Aurora at my latitudes.
           | 
           | Do we just have better sensing now, or is there some cycle on
           | a period longer than a few years? Or maybe I'm crazy and just
           | never noticed.
        
             | awesome_dude wrote:
             | We've just passed the 11 year peak - the sun spot activity
             | has a period of around 11 years.
        
             | 0manrho wrote:
             | Mid to late 2025 was the peak of an 11 year solar cycle
             | (25th one since we've started keeping track). We're on the
             | trailing end of that peak activity now, which is why the
             | past year/several months has seemed so active compared to
             | recent years past, and should decrease significantly (in
             | frequency and intensity) as 2026 progresses.
             | 
             | There was also a fairly significant geomagnetic storm back
             | in November of 2025 as well.
             | 
             | You can see the data here at NOAA's Space Weather site
             | https://www.swpc.noaa.gov/products/solar-cycle-progression
        
             | ErroneousBosh wrote:
             | > Have we been having these more recently?
             | 
             | Yes, for suitable values of "recently".
             | 
             | > And I also never remember seeing Aurora at my latitudes.
             | 
             | How old are you?
             | 
             | If you're younger than say your mid-40s you probably won't
             | remember the early 80s, which is the last time we had a
             | solar maximum that really came to anything.
             | 
             | Solar activity rises and falls on an 11-year cycle, and
             | right now we're experiencing quite a peak. The previous
             | three, peaking in 2014, 2011, and 1989 were a bit of a
             | bust.
             | 
             | There was a massive peak in 1979 and I can remember my dad
             | showing me the aurora when I was about six or seven - it
             | seemed to be present most nights over the winter. That was
             | also around the time of the CB Radio craze, where
             | atmospheric conditions were such that you could use "skip"
             | - bouncing radio signals off the highly-charged ionosphere
             | - to talk to people hundreds of miles away as if they were
             | just down the road, even on the comparatively high
             | frequencies that CB used. There was a bit of a peak in the
             | late 80s, and some good RF propagation too, as well as some
             | incredible aurora - although the big one I remember was in
             | about the end of 1991, early 1992.
             | 
             | We had absolutely blistering hot summers followed by really
             | cold and snowy winters, too, kind of like we're having at
             | the moment.
             | 
             | If the solar cycles have a longer repeating cycle of
             | intensity on the scale of a hundred years or so (and it
             | looks a bit like they do) then the next solar maximum in
             | about 2036 is going to be even bigger.
        
           | keepamovin wrote:
           | This is also related to weaker solar events leading to
           | stronger Earth storms due to Earth's weakening magnetic
           | field.
        
           | kelseydh wrote:
           | Disturbance storm time index (DST) is a better measure of
           | peak intensity as KP is just a weighted average of the
           | intensity from the last three hours across monitoring
           | stations.
           | 
           | The May 2024 G5 electrical storm had a peak measured DST of
           | -412 nT: https://en.wikipedia.org/wiki/May_2024_solar_storms
           | 
           | The Carrington Event had an estimated peak DST of -800 nT to
           | -1750 nT, but no one really knows:
           | https://en.wikipedia.org/wiki/Carrington_Event
        
         | neonmagenta wrote:
         | so more of a 'bad storm here and there' level?
        
         | 8bitsrule wrote:
         | G4: " Induced pipeline currents affect preventive measures, HF
         | radio propagation sporadic..."
         | 
         | G5: " Pipeline currents can reach hundreds of amps, HF (high
         | frequency) radio propagation may be impossible in many areas
         | for one to two days..."
        
           | gexla wrote:
           | "Cool! What's G13 do?" - Bill Hicks
           | 
           | Looks like G5 is the highest level and the scale system is
           | used by NOAA.
        
             | serf wrote:
             | >"Cool! What's G13 do?" - Bill Hicks
             | 
             | I hear that bit in my head every time a new plane or weapon
             | designation is announced, glad to hear it stuck with others
             | too.
        
             | ck2 wrote:
             | G13 could be a gamma-ray burst from a collapsing star less
             | than 100 light years from earth
             | 
             | in which case, don't worry about it as we won't be around
             | to worry about it further
             | 
             | astro-physics is AMAZING (until it kills you lol)
        
           | gosub100 wrote:
           | "Free Energy!"
        
             | autoexec wrote:
             | That's the nice thing about solar power, but it's still a
             | limited time offer
        
               | smcnally wrote:
               | Indirect Nuclear Fusion
        
             | tclancy wrote:
             | I wonder if they're still putting out music ...
        
           | mcs5280 wrote:
           | Sam Altman has entered an agreement to acquire all future G4
           | and G5 energy
        
           | justinator wrote:
           | Waiting until it's like a G6, Like a G6
           | 
           | Now I'm feelin' so fly like a G6
        
             | miduil wrote:
             | Thanks, really had to listen to the song.
             | 
             | https://www.youtube.com/watch?v=DWRJC8ap9B4
        
           | dmurray wrote:
           | HF propagation is flaky at the best of times. It's affected
           | by the day/night cycle and by the weather.
        
         | non- wrote:
         | > Biological: Unavoidable radiation hazard to astronauts on
         | EVA; passengers and crew in high-flying aircraft at high
         | latitudes may be exposed to radiation risk.
         | 
         | Anyone have a sense of magnitude for this advisory? How much
         | more radiation should an airline passenger expect to receive
         | during a G4 event than normal?
        
           | inatreecrown2 wrote:
           | roughly up to 5-10 times the normal dose.
        
             | NeoInHacker wrote:
             | sounds "it's okey" ?
        
               | jojobas wrote:
               | Nowhere near lifetime occupational dose limits.
        
         | Helmut10001 wrote:
         | Interestingly, there are about 100 events of this severity (G4)
         | per cycle, and a single cycle lasts 11 years. This means there
         | are about nine G4 events on average per year.
        
           | tomr_stargazer wrote:
           | Note, however, that the solar cycle [0] is so named due to
           | its minimum and maximum: the most severe events will be
           | clustered around the maximum, rather than spread out over the
           | whole cycle (as your comment suggested) - so the "nine G4
           | events on average per year" is mathematically true but not so
           | helpful.
           | 
           | [0]: https://en.wikipedia.org/wiki/Solar_cycle
        
         | velocity3230 wrote:
         | This was an S4 event, however.
        
           | velocity3230 wrote:
           | Belay that. The G-value was high too.
        
         | 9dev wrote:
         | The scale seems capped at a pretty low upper end? It feels like
         | with all the mindbogglingly huge numbers usually involved when
         | talking about space, there must be much, much worse events
         | possible. Is it just that we don't know enough about them due
         | to lack of experience that these aren't included?
        
           | poizan42 wrote:
           | https://en.wikipedia.org/wiki/Carrington_Event
           | 
           | But having been in 1859 we only have estimates on what the
           | consequences would be in the modern world. But pretty grim at
           | the looks of it.
        
       | Animats wrote:
       | PJM had some geomagnetic disturbance warnings, but did not
       | progress to the alert stage or grid re-configuation actions. So,
       | no US power grid problems.                   104955 Warning
       | Geomagnetic Disturbance Warning 01.19.2026 14:30          PJM-RTO
       | A Geomagnetic Disturbance Warning has been issued for
       | 14:30 on 01.19.2026 through 16:00 on 01.19.2026 .         A GMD
       | warning of K8 or greater is in effect for this period.
       | End time: 01.19.2026 16:00
       | 
       | (All times are prevailing Eastern US time)
       | 
       | I've posted on this before, for other warnings. Not going to
       | repeat that.
        
         | cbdevidal wrote:
         | Thank you, that's a really handy resource. Shared with my
         | prepper friends.
         | 
         | https://emergencyprocedures.pjm.com/ep/pages/dashboard.jsf
        
       | PlatoIsADisease wrote:
       | Years ago I was concerned about this and made a plan with my wife
       | for what to do if she was at work.
       | 
       | But now we have a bunch of kids in different schools and haven't
       | updated our plan.
       | 
       | Does anyone have a plan for what happens if we have a really bad
       | event?
        
         | fuzzer371 wrote:
         | Keep a couple days water and food on hand, go up to the pub,
         | have a pint, and wait for this all to blow over.
        
           | JoshTriplett wrote:
           | With how much modern cars rely on electronics, I would not
           | try to drive during such an event.
        
             | lxgr wrote:
             | Solar flares are only dangerous to very long conductors.
        
               | luxuryballs wrote:
               | so cancel the limo?
        
             | whyleyc wrote:
             | It's ok - The Winchester is within walking distance.
        
               | jrgd wrote:
               | Omg i watched this yesterday!
        
             | throwaway81523 wrote:
             | That's a safety feature. It prevents you from drinking and
             | driving if you go to a pub during a solar flare. :)
        
             | jrgd wrote:
             | No one would drive to the pub anyway. Better walking back
             | home...
        
               | JoshTriplett wrote:
               | Valid. I think I have such an ingrained different set of
               | assumptions (a pub being just another kind of place for
               | food, and "going to" anything involving a form of
               | transportation) that that didn't even occur to me.
        
         | Tepix wrote:
         | Buy a bit of extra food and water.
        
           | y1n0 wrote:
           | And toilet paper! Rolls and rolls of toilet paper!
        
         | hnuser123456 wrote:
         | A really bad event would be that long-distance transmission
         | lines act like antennas and pick up millions of volts and blow
         | up all the transformers.
         | 
         | I don't know how much you can plan for that other than "if it
         | happens, try to get home", and then all the usual prepper
         | stuff.
        
         | swader999 wrote:
         | First rule of fight club...
        
         | rootusrootus wrote:
         | For a really bad event that managed to blow a lot of
         | transformers (presumably due to grid operators not seeing it
         | coming) ... well, take up farming.
        
         | myself248 wrote:
         | Pray for clear skies and go out and watch the beautiful aurora,
         | silly!
         | 
         | Depending on the kids' ages, you can teach them quite a lot
         | about the Earth's magnetic field and why the aurora
         | concentrates at the poles, how the high-energy particles light
         | up the sky (it's a lot like a neon light), and how the
         | atmosphere shields us from any danger despite the spectacular
         | show.
        
         | internet_points wrote:
         | Disconnect your telegraph batteries and run on aurora power
         | only
        
         | esskay wrote:
         | Feel a bit sensationalistic. It happens, it's not rare, and
         | we've always got on with life perfectly fine.
        
       | _carbyau_ wrote:
       | Weirdly, while the site in question is "blaring klaxons!" there
       | are more "cool night lights!" posts than concern.
        
         | guerrilla wrote:
         | > while the site in question is "blaring klaxons!"
         | 
         | No, it isn't. It clearly says everything is under control but
         | it would be good to keep an eye on it.
        
         | zamadatix wrote:
         | Unless you're in space, a large scale electrical operator, or
         | relying on HF radio there isn't much reason to be interested
         | other than the lights for a G4 (what this is currently classed
         | as).
        
           | pvab3 wrote:
           | my Telecaster sure was noisy this morning but I didn't think
           | much of it
        
         | rzzzt wrote:
         | Blaring Klaxons! https://youtu.be/LX2KX0OaofI
        
       | bashtoni wrote:
       | Australian Bureau of Meteorology advisory for visible aurora:
       | https://www.sws.bom.gov.au/Aurora
        
         | hahahahhaah wrote:
         | Is that tonight or last night?
        
           | bashtoni wrote:
           | It was only issued this morning Australian time, so I presume
           | it's for tonight.
        
         | jp0d wrote:
         | Are there any resources to track Aurora sightings or predicted
         | sightings?
        
           | stubish wrote:
           | At the bottom right of that page is a subscribe link, with a
           | number of different alerts and lists to subscribe to.
        
             | jp0d wrote:
             | Thank you!
        
           | lakid wrote:
           | https://aurora-alerts.uk/ Ignore the UK TLD, this tracks
           | global sightings
        
             | jp0d wrote:
             | Ahh thank you! I saw a few photos from last night's Aurora
             | sightings down here in Vic, Australia. Maybe next time! :)
        
         | aussieguy1234 wrote:
         | Worth noting that Kp, which many talk about in discussions
         | online, is more or less useless for anyone in Australia or the
         | southern hemisphere. Lots of beginner Aurora chasers here get
         | tripped up by that.
         | 
         | What is useful is KAus and the G index, KAus is shown on this
         | page, so thats what i'll be tracking.
        
       | aussieguy1234 wrote:
       | I'll be going out tonight if this continues into Australian night
       | time hours.
       | 
       | At this strength, I could see the full display including colors
       | with my naked eye in Melbourne, May 11th 2024. This storm is
       | slightly stronger than that event.
        
         | ikr678 wrote:
         | I'll be attempting to get some photos/footage from Esperance.
        
           | defrost wrote:
           | There's a high triple threat bar for Astro photos sourced
           | from Western Australia.
           | 
           | https://apod.nasa.gov/apod/ap110529.html
           | 
           | If you manage to pull off the Aurora Australis above a triple
           | curl at The Right with a shark body surfing into the green
           | room ... the internet will explode.
        
       | rediguanayum wrote:
       | Moon should be good too to see Aurora tonight: waxing crescent 1%
       | https://www.moongiant.com/phase/today/
        
       | ferguess_k wrote:
       | Darn Montreal is still too south. Wish I were in Winnipeg.
        
       | tigerlily wrote:
       | Hopefully it's clear space weather for Artemis II coming up. I
       | wonder what they do if it's inclement _en route_?
        
         | perihelions wrote:
         | There's not that much they can do. It's often discussed that if
         | the extreme August 1972 solar storm had overlapped with an
         | Apollo mission (it didn't), it would have acutely sickened the
         | astronauts.
         | 
         | https://en.wikipedia.org/wiki/August_1972_solar_storms#Human...
         | 
         | > _" Had a mission been taking place during August, those
         | inside the Apollo command module would have been shielded from
         | 90% of the incoming radiation. However, this reduced dose could
         | still have caused acute radiation sickness if the astronauts
         | were located outside the protective magnetic field of Earth,
         | which was the case for much of a lunar mission. An astronaut
         | engaged in EVA in orbit or on a moonwalk could have experienced
         | severe radiation poisoning, or even absorbed a potentially
         | lethal dose."_
         | 
         | The Orion capsule's contingency plan looks something like this:
         | 
         | > _" To protect themselves, astronauts will position themselves
         | in the central part of the crew module largely reserved for
         | storing items they'll need during flight and create a shelter
         | using the stowage bags on board. The method protects the crew
         | by increasing mass directly surrounding them, and therefore
         | making a denser environment that solar particles would have to
         | travel through, while not adding mass to the crew module
         | itself."_
         | 
         | https://www.nasa.gov/missions/artemis/orion/scientists-and-e...
        
           | xattt wrote:
           | For All Mankind "illustrated" a solar storm at surface-level
           | of the moon, including "boiling" regolith. I wonder how
           | embellished this was, or whether particle bombardment would
           | actually cause this.
           | 
           | My mind goes to the working mechanism of eidophor projectors,
           | where oil on the projection bowl does indeed deform under
           | electron beam exposure.
        
       | frzen wrote:
       | I had the most intensely coloured lights visible in the west of
       | Ireland. I've seen them a few times before but never like this.
       | Phones were capturing them in video not just long exposures.
       | 
       | Not sure what the best service is to be alerted ahead of time.
       | Apparently it'll be strong here again at 6am according to some of
       | the apps some random people were waving around.
        
         | ortusdux wrote:
         | There are several apps that do a good job of alerting users. I
         | use "Aurora Pro", which I prefer because it checks cloud cover
         | and lets you set alert thresholds based on viewing probability.
        
           | King-Aaron wrote:
           | I woke up to a notification from aurora pro today, I'd
           | forgotten I had the app. This would explain it
        
       | cbeach wrote:
       | Probably a stupid question, but should I unplug my EV? (UK)
        
         | qayxc wrote:
         | No need. Wrong type of solar event. You might be able to see
         | auroras, though. I saw some a couple of hours ago.
        
         | jacquesm wrote:
         | No.
        
         | _blk wrote:
         | Yes! Absolutely, but only if you want to drive it.
        
       | aliljet wrote:
       | I wonder if we're going to see an aurora over Seattle tonight?
        
         | throwway120385 wrote:
         | Too much light pollution. You'd have to get well outside of the
         | city. I looked at the weather last night and I think there
         | might have been some trails on Tiger where you would've seen it
         | with headlamp off.
         | 
         | In Seattle you can barely see planets.
        
       | tramtrist wrote:
       | We never get aurora in Japan :(
        
         | pilaf wrote:
         | Hokkaido got some back in November:
         | https://www.asahi.com/ajw/articles/16155623
        
           | tramtrist wrote:
           | Yeah I figure Hokkaido may get a taste but we here in Honshu
           | never do :'(
        
       | WhitneyLand wrote:
       | How rare is this?
       | 
       | G4 storms are ~100 per solar cycle (~11 years).
       | 
       | So roughly 9 G4 events/year on average.
        
         | burnt-resistor wrote:
         | Like 20-25 years rare according to some space weather youtuber.
        
           | creatonez wrote:
           | > some space weather youtuber
           | 
           | Please stop watching that guy, he is a total fraud and knows
           | nothing about physics.
        
         | tbrownaw wrote:
         | But they should mostly be in the same part of the cycle rather
         | than spread evenly.
         | 
         | It probably wouldn't make sense to calculate "average snow days
         | per month" across an entire calendar year (in most places...),
         | this is the same thing.
        
         | velocity3230 wrote:
         | This is an S4, though.
        
           | velocity3230 wrote:
           | Belay that. The G-value was high too.
        
         | rapht wrote:
         | This is an S4. Last S4 event was in October 2003.
        
       | drmpeg wrote:
       | Although everyone is interested in visible aurora, the proton
       | flux is also really impressive. It peaked at 37,000 pfu at 1910Z.
       | The highest ever recorded was 43,500 pfu in March 1991.
        
       | JoeDaDude wrote:
       | There is a video update from the NOAA Space Weather Prediction
       | Center. (I could only find this on Facebook)
       | https://www.facebook.com/reel/1190509063198524
        
       | burnt-resistor wrote:
       | Up to G-5 possibly. Cell phone visible in dark areas throughout
       | most of CONUS.
       | 
       | It was mentioned that air travel ionizing radiation exposure
       | increases during geomagnetic storms. I'd consider pausing travel
       | for a couple of days to not be a guinea pig because there's not
       | enough data to consider it safe. If anyone absolutely must fly
       | tonight, it'd be interesting if they were to take a high
       | sensitivity dosimeter to see what happens.
        
         | garbagewoman wrote:
         | Not sure how to deal with this kind of wildly unbalanced risk
         | assessment
        
       | Kunsang wrote:
       | Discussion of the event
       | https://community.spaceweatherlive.com/topic/4210-x19-cme/
        
         | neogodless wrote:
         | This is definitely not a language I speak!
         | 
         | Flux and bZ!
        
           | imp0cat wrote:
           | Surely you must be familiar with the flux capacitor? ;)
        
           | Kunsang wrote:
           | I understand maybe half of this, but I followed the
           | discussion and knew when it was about time to go outside.
        
         | fnands wrote:
         | Damn, I love finding some hyper-specific forums like this one.
         | 
         | Sooo much jargon.
        
       | nbf_1995 wrote:
       | Title says "S4" solar radiation event, but the linked page says
       | "G4" geomagnetic storm
        
       | anon115 wrote:
       | any effects on the human body??
        
         | internet_points wrote:
         | Depends. If you're outside at night and tilt your head up, the
         | Default Mode Network of your brain may be temporarily
         | suppressed, while dopamine may increase.
        
       | andrewinardeer wrote:
       | Any tips on best practices in how one can protect homelab rigs
       | from a Carrington level event? Let's say we were given two days
       | notice that the mother of all S4s was inbound. Just switch
       | everything off?
       | 
       | What if one of my homelabs needed 100% uptime to meet my wife's
       | SLA for messaging? Is this able to be protected?
        
         | rootusrootus wrote:
         | AFAIK the risk is for long transmission lines. So your
         | equipment at home is not really in any danger, as long as there
         | is not a major surge on the transmission lines that makes it
         | all the way to your house. If that happens, well, losing the
         | home lab is probably no longer the issue.
        
         | idatum wrote:
         | Discontinue use of your telegraph system.
         | 
         | Perhaps though you will still be able to continue to send and
         | receive messages despite having disconnected your power supply.
         | [1]
         | 
         | [1]
         | https://babel.hathitrust.org/cgi/pt?id=uva.x001679510&seq=40...
        
         | amluto wrote:
         | Not much? As I understand it, the major effects are in very
         | long wires. Long wires can have get massive induced currents.
         | But your homelab is unlikely to have long wires or very large
         | loops. Ethernet wires are limited to 100m, and unshielded
         | Ethernet is transformer-isolated to well over 1kV.
         | 
         | Shielded Ethernet could plausibly have issues with induced
         | current on the shield. PoE might be less immune than ordinary
         | Ethernet depending on what you're doing with it, although well-
         | behaved devices should be isolated. If you have a cable ISP,
         | the cable shield might get toasty, although it's likely to be
         | grounded close enough to your house that any damage will be
         | upstream.
         | 
         | Your 100% uptime will be tricky if your ISP goes down or you
         | lose power.
        
         | tbrownaw wrote:
         | Make sure you have a surge protector or ups, in case it makes
         | the power grid go funky. Which you should have anyway.
         | 
         | Also, it could be a convenient excuse to upgrade to fiber
         | internet service if you haven't already. (Yes, excuse.
         | Equipment _should_ have more than good enough isolation to not
         | care.)
        
           | johncolanduoni wrote:
           | Even if you don't have fiber all the way into your house,
           | most cable internet terminates pretty close to the home these
           | days. It kind of has to, since bandwidth has gone way up and
           | as a result they can't put very many subscribers on the same
           | termination system.
           | 
           | We didn't really understand this kind of thing when the
           | Carrington event happened, so nobody knows for sure, but
           | estimates for induced voltage on long conductors are usually
           | something on the order of 20V/km. So for a 5 km long coaxial
           | cable, you're only talking about ~120V of induced potential
           | difference (i.e. the same voltage as a residential plug in
           | the US). When people are analyzing the potential damage from
           | this kind of electromagnetic disturbance (E3 is the term
           | you'll see, based on analysis of nuclear EMP which has other
           | components that you don't see in geomagnetic storms
           | regardless of severity), it's mostly about _really_ long
           | conductors, like on the order of 100km.
        
       | lgats wrote:
       | https://www.ieso.ca/Sector-Participants/RSS-Feeds/Day-0-Advi...
       | 
       | https://www.misoenergy.org/markets-and-operations/notificati...
       | 
       | https://www.ercot.com/services/comm/mkt_notices/notices
       | 
       | https://emergencyprocedures.pjm.com/ep/pages/dashboard.jsf
        
       | _blk wrote:
       | Nice. And it's somewhat relieving to read this over a Starlink
       | connection.
        
       | AnishLaddha wrote:
       | fascinating, hope our critical infrastructure can handle this.
       | how long does something like this last, and will it have an
       | effect on artemis 2?
       | 
       | hypothetical: if a carrington event-esque storm happens during
       | the mission, how badly will the houston <-> orion module
       | communication links be affected?
        
       | sparin9 wrote:
       | TL;DR: A severe (G4-level) geomagnetic storm hit Earth on January
       | 19, 2026 due to a solar coronal mass ejection. It can disrupt
       | power grids, GPS, satellite systems, and radio communications,
       | while creating visible aurora displays at higher latitudes.
        
       | lukan wrote:
       | I missed it (seeing the Aurora) .. are there any reliable alerts
       | for this sort of event, that do not alert me about anything else,
       | but really only such big events?
        
         | cvt7bm wrote:
         | https://www.swpc.noaa.gov/content/subscription-services
        
           | lukan wrote:
           | Thanks, that seems exactly what I was looking for. (Now I
           | have to figure out the best way to get a alert to my phone if
           | my inbox receives such a mail, probably easiest to use a a
           | mailadress just for this case and then treat this emailadress
           | different)
        
         | MrGilbert wrote:
         | One caveat is, that these events cannot be forecasted in the
         | same way as weather on earth can. You usually only have a lead
         | time of 15 - 45 minutes. See also
         | https://www.swpc.noaa.gov/content/aurora-tutorial
        
           | lukan wrote:
           | Sure. But if I am awake, those 15 minutes are enough to get
           | dressed and go outside.
           | 
           | Yesterday I just would have had to walk to the balkony to see
           | it, but I was busy with some frustrating coding problem
           | instead ..
        
             | Levitating wrote:
             | same, I was awake for the whole night but completely missed
             | it
        
         | vachina wrote:
         | On iOS there's an app literally called "Aurora".
         | 
         | It will notify you when you're in an area with a high Kp (or
         | above a Kp you specify).
        
         | albertzeyer wrote:
         | I had registered for alerts on https://aurorasaurus.org/. But
         | that alert was sent way too late for me (strongest lights were
         | yesterday around 10-11 PM, and the notification was sent 2 AM
         | today). But I was very lucky and just noticed the lights by
         | accident on my way home.
        
       | cess11 wrote:
       | I live somewhat close to the arctic circle and the aurora has
       | been exceptional lately. One recent evening it looked like there
       | was a massive city behind the cloud cover, and a few nights
       | before when the sky was clear I watched enormous green flames for
       | hours.
        
         | internet_points wrote:
         | Aha, you probably witnessed a glimpse of Cittagazze. You can
         | capture it in photograms with a special emulsion:
         | https://hisdarkmaterials.fandom.com/wiki/Aurora?file=Citt%C3...
        
       | brador wrote:
       | What strength would destroy the sensor?
        
       | jokull wrote:
       | As seen from my apartment in Reykjavik Iceland:
       | https://ss.solberg.is/89N0qS7T
        
         | smcnally wrote:
         | That's beautiful. But you get aurora even sans G4, true? Was
         | this more intense and spectacular?
        
           | jokull wrote:
           | Yes - not seen it this red though.
        
       | jesprenj wrote:
       | Our network router in our radio station started acting crazy at
       | 22:00:40 Europe/Ljubljana time. Uptime monitoring via HTTPS
       | reported downtime for 5 minutes, but our radio archive that
       | records audio over LiveWire recorded some bitcrushing effects for
       | 5 minues. Maybe our Mikrotik hEX was flipping some bits?
       | Recording from the radio archive:
       | https://splet.4a.si./dir/solar.mp3
        
         | justsomehnguy wrote:
         | Yes, sounds similar to a corrupted digital audio.
         | 
         | Replace hex with something more robust, at least with an actual
         | metallic case.
        
           | jesprenj wrote:
           | Yes, that is planned. As soon as we get more money (:
        
           | noumenon1111 wrote:
           | *Gemini Tech Tip #624:* Boost your Wi-Fi _and_ spiritual
           | resilience by wrapping your router in aluminum foil! Protect
           | against solar flares, reptilian packet theft, and basic
           | physics. Turn it into a family craft: make and decorate foil
           | router cozies and matching foil hats, then browse Reddit and
           | /or the park, seeking fellow shiny-headed believers.
        
         | motrm wrote:
         | Sounds like a dialup modem at about 3:30 :)
         | 
         | How sure are we the aliens aren't trying to dial in?
        
       | markonen wrote:
       | Just had my first uncorrectable memory read error on our servers
       | in 10 years or so today (in Sacramento). I'd like to think it's
       | related because the alternative (buying new DIMMs) is too
       | horrifying to contemplate
        
         | buildbot wrote:
         | Last major storm I saw a significant number of single bit
         | errors on my main server - never happened again, still using
         | the same ram. So +1 anecdote
        
           | dosnem wrote:
           | Is this detectable without some parity checks?
        
             | danielheath wrote:
             | No, but ECC ram gives you _hardware_ parity checks, which
             | is much faster and doesn't require you to change your code.
        
       | markus_zhang wrote:
       | Well I didn't see anything last night (In Eastern Canada),
       | probably because there was too much light in the suburb. Now the
       | aurora "area" turns back to Europe and Asia, I hope you guys
       | enjoy it!
       | 
       | Judging by this picture:
       | https://services.swpc.noaa.gov/images/animations/ovation/nor... ,
       | I think in a few hours the whole North Europe can see it very
       | clearly.
        
         | T0Bi wrote:
         | Your URL is broken (for me)
        
       | juliend2 wrote:
       | Might be a coincidence but for the first time last night, my
       | son's sleep projector[0] didn't stop after 1h like it does
       | normally.
       | 
       | I guess this could be related to it? (we are in Montreal)
       | 
       | I doubt these toys are protected from those kinds of events.
       | 
       | [0] https://www.amazon.com/Fisher-Price-Settle-Sleep-
       | Projection-...
        
       | mrbluecoat wrote:
       | Verizon will probably retroactively blame their outage on it.
        
       | notfish wrote:
       | Had to stay up until 2am shutting down our spacecraft. Stupid sun
       | hates to see me get a solid night's sleep.
        
         | aclindsa wrote:
         | What spacecraft is your spacecraft?
        
           | phendrenad2 wrote:
           | And where did you park it? And what's the combination to open
           | the hatch?
        
       | wafflemaker wrote:
       | What are the best apps to get notified when there's a geomagnetic
       | storm /chances to see Aurora? Preferably not only for USA.
        
       | trashface wrote:
       | Scott Manley just did a video on radiation shielding:
       | https://www.youtube.com/watch?v=DJcbevbBzsc
       | 
       | Based on that, I presume the astronauts on the ISS will need to
       | take cover due to this event
        
       | johng wrote:
       | These solar events can cause loss of communication with
       | satellites making avoidance maneuvers hard or impossible. This
       | article just came out recently and is definitely scary:
       | https://www.universetoday.com/articles/28-days-to-disaster-w...
        
       | JumpCrisscross wrote:
       | Any aurora luck for those of us in the Rockies? (Near
       | Yellowstone.)
        
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       (page generated 2026-01-20 23:00 UTC)