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Level S4 solar radiation event

623 points3 daysswpc.noaa.gov
jjcm3 days ago

If anyone is interested in what "G4" means in context, here's the scale: https://www.swpc.noaa.gov/noaa-scales-explanation

Helmut100013 days ago

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_stargazer3 days ago

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

8bitsrule3 days ago

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..."

mcs52803 days ago

Sam Altman has entered an agreement to acquire all future G4 and G5 energy

gexla3 days ago

"Cool! What's G13 do?" - Bill Hicks

Looks like G5 is the highest level and the scale system is used by NOAA.

ck22 days ago

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)

serf2 days ago

>"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.

justinator3 days ago

Waiting until it's like a G6, Like a G6

Now I'm feelin' so fly like a G6

miduil3 days ago

Thanks, really had to listen to the song.

https://www.youtube.com/watch?v=DWRJC8ap9B4

sebastiennight2 days ago

[dead]

gosub1003 days ago

"Free Energy!"

autoexec3 days ago

That's the nice thing about solar power, but it's still a limited time offer

smcnally2 days ago

Indirect Nuclear Fusion

tclancy2 days ago

I wonder if they’re still putting out music …

dmurray3 days ago

HF propagation is flaky at the best of times. It's affected by the day/night cycle and by the weather.

9dev3 days ago

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?

poizan422 days ago

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.

irthomasthomas3 days ago

We are at kp 8.67. The Carrington event was a kp 9

ianruh3 days ago

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

repeekad3 days ago

Queue Chernobyl documentary clip measuring the radiation as low because that’s as high the meter went

+1
wyldfire3 days ago
+2
celsoazevedo3 days ago
banku_brougham2 days ago

kp 9 - not great, not terrible

kelseydh3 days ago

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

keepamovin3 days ago

This is also related to weaker solar events leading to stronger Earth storms due to Earth's weakening magnetic field.

echelon3 days ago

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.

0manrho3 days ago

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

ErroneousBosh2 days ago

> 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.

awesome_dude3 days ago

We've just passed the 11 year peak - the sun spot activity has a period of around 11 years.

xeckr3 days ago

Looks like we get these for about 60 days for periods lasting 11 years.

non-3 days ago

> 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?

inatreecrown23 days ago

roughly up to 5-10 times the normal dose.

NeoInHacker3 days ago

sounds "it's okey" ?

jojobas3 days ago

Nowhere near lifetime occupational dose limits.

velocity32303 days ago

This was an S4 event, however.

velocity32303 days ago

Belay that. The G-value was high too.

neonmagenta3 days ago

so more of a 'bad storm here and there' level?

markonen2 days ago

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

buildbot2 days ago

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

dosnem2 days ago

Is this detectable without some parity checks?

danielheath2 days ago

No, but ECC ram gives you _hardware_ parity checks, which is much faster and doesn’t require you to change your code.

bartman3 days ago

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.

rob743 days ago

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...

ccozan3 days ago

I am south-west of Munich and with a perfect clear sky I could only see stars, one meteor, and that's it.

fransje262 days ago

It was visible in the 22:00-23:00 time window. Here in the south west, the sky started turning green around 22:30.

Kyro382 days ago

We also had them in Grenoble, south of France.

madduci3 days ago

Can confirm, I've seen pink/green glow over Berlin Sky (and pictures as well)

fluxflexer3 days ago

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!

madduci3 days ago

I'm Berlin was around 22-23 o'clock visible

jacquesm3 days ago

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.

CalRobert3 days ago

ahh I just went outside (south of Utrecht) and saw nothing. Maybe too much light pollution.

jacquesm2 days ago

I'm lucky in that I was close to the IJsselmeer.

karim793 days ago

I was just out at a dog park and saw nothing! We have clear skies. I can't believe I missed this.

danesparza2 days ago

Next time take a long exposure picture with your phone. You might be able to see it that way.

paulmist3 days ago

Also seen in the Netherlands!

TacticalCoder3 days ago

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.

Tachyooon3 days ago

Could you see it from the inner city or only closer to the edges?

bartman3 days ago

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...

Tachyooon3 days ago

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.

thrawn0r3 days ago

Saw it in Fhain as well over Ostkreuz station

marc_g3 days ago

Oh really? Oh no I missed it! Is it going to happen again today?

miduil3 days ago

Nice, you can already see some solar flares in Austria again.

https://www.foto-webcam.eu/webcam/kleinfleisskees/

https://www.foto-webcam.eu/

qwertox3 days ago

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

irjustin3 days ago
chakintosh2 days ago

Crazy how many starlink satellite trains can be seen here. I spotted 4 trains, in that one cam

irjustin2 days ago

Isn't that just 4 sats and it looks like that because of long exposure?

jcims2 days ago

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

caseyohara3 days ago

Those images around 19:00 are amazing. Thanks for sharing.

frzen3 days ago

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.

ortusdux3 days ago

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-Aaron3 days ago

I woke up to a notification from aurora pro today, I'd forgotten I had the app. This would explain it

jesprenj2 days ago

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

justsomehnguy2 days ago

Yes, sounds similar to a corrupted digital audio.

Replace hex with something more robust, at least with an actual metallic case.

noumenon11112 days ago

*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.

jesprenj2 days ago

Yes, that is planned. As soon as we get more money (:

motrm2 days ago

Sounds like a dialup modem at about 3:30 :)

How sure are we the aliens aren't trying to dial in?

andrewinardeer3 days ago

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?

amluto3 days ago

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.

rootusrootus3 days ago

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.

idatum3 days ago

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...

tbrownaw3 days ago

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.)

johncolanduoni3 days ago

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.

Animats3 days ago

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.

cbdevidal3 days ago

Thank you, that's a really handy resource. Shared with my prepper friends.

https://emergencyprocedures.pjm.com/ep/pages/dashboard.jsf

lukan3 days ago

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?

lukan3 days ago

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)

vachina2 days ago

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).

MrGilbert2 days ago

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

lukan2 days ago

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 ..

Levitating2 days ago

same, I was awake for the whole night but completely missed it

albertzeyer2 days ago

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.

dschuessler3 days ago

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.

delusional3 days ago

Looking at the aspect ratio (and working in a bank) it's worse than that. That's a powerpoint slide.

delfinom3 days ago

Not like someone with poor vision is going to be able to see the aurora borealis that results

/s

drmpeg3 days ago

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.

rediguanayum3 days ago

Moon should be good too to see Aurora tonight: waxing crescent 1% https://www.moongiant.com/phase/today/

bashtoni3 days ago

Australian Bureau of Meteorology advisory for visible aurora: https://www.sws.bom.gov.au/Aurora

aussieguy12343 days ago

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.

jp0d3 days ago

Are there any resources to track Aurora sightings or predicted sightings?

lakid3 days ago

https://aurora-alerts.uk/ Ignore the UK TLD, this tracks global sightings

jp0d2 days ago

Ahh thank you! I saw a few photos from last night's Aurora sightings down here in Vic, Australia. Maybe next time! :)

stubish3 days ago

At the bottom right of that page is a subscribe link, with a number of different alerts and lists to subscribe to.

jp0d2 days ago

Thank you!

hahahahhaah3 days ago

Is that tonight or last night?

bashtoni3 days ago

It was only issued this morning Australian time, so I presume it's for tonight.

Kunsang3 days ago
neogodless3 days ago

This is definitely not a language I speak!

Flux and bZ!

imp0cat2 days ago

Surely you must be familiar with the flux capacitor? ;)

Kunsang2 days ago

I understand maybe half of this, but I followed the discussion and knew when it was about time to go outside.

fnands3 days ago

Damn, I love finding some hyper-specific forums like this one.

Sooo much jargon.

aussieguy12343 days ago

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.

ikr6783 days ago

I'll be attempting to get some photos/footage from Esperance.

defrost3 days ago

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.

PlatoIsADisease3 days ago

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?

hnuser1234563 days ago

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.

myself2483 days ago

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.

rootusrootus3 days ago

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.

fuzzer3713 days ago

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.

JoshTriplett3 days ago

With how much modern cars rely on electronics, I would not try to drive during such an event.

whyleyc3 days ago

It’s ok - The Winchester is within walking distance.

jrgd3 days ago

Omg i watched this yesterday!

lxgr3 days ago

Solar flares are only dangerous to very long conductors.

luxuryballs3 days ago

so cancel the limo?

throwaway815233 days ago

That's a safety feature. It prevents you from drinking and driving if you go to a pub during a solar flare. :)

jrgd3 days ago

No one would drive to the pub anyway. Better walking back home…

JoshTriplett3 days ago

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.

internet_points3 days ago

Disconnect your telegraph batteries and run on aurora power only

esskay3 days ago

Feel a bit sensationalistic. It happens, it's not rare, and we've always got on with life perfectly fine.

Tepix3 days ago

Buy a bit of extra food and water.

y1n03 days ago

And toilet paper! Rolls and rolls of toilet paper!

swader9993 days ago

First rule of fight club...

WhitneyLand3 days ago

How rare is this?

G4 storms are ~100 per solar cycle (~11 years).

So roughly 9 G4 events/year on average.

tbrownaw3 days ago

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.

rapht2 days ago

This is an S4. Last S4 event was in October 2003.

velocity32303 days ago

This is an S4, though.

velocity32303 days ago

Belay that. The G-value was high too.

burnt-resistor3 days ago

Like 20-25 years rare according to some space weather youtuber.

creatonez3 days ago

> some space weather youtuber

Please stop watching that guy, he is a total fraud and knows nothing about physics.

notfish2 days ago

Had to stay up until 2am shutting down our spacecraft. Stupid sun hates to see me get a solid night’s sleep.

aclindsa2 days ago

What spacecraft is your spacecraft?

phendrenad22 days ago

And where did you park it? And what's the combination to open the hatch?

markus_zhang2 days ago

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.

T0Bi2 days ago

Your URL is broken (for me)

juliend22 days ago

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-...

jokull2 days ago

As seen from my apartment in Reykjavík Iceland: https://ss.solberg.is/89N0qS7T

smcnally2 days ago

That’s beautiful. But you get aurora even sans G4, true? Was this more intense and spectacular?

jokull2 days ago

Yes - not seen it this red though.

trashface2 days ago

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

cess113 days ago

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_points3 days ago

Aha, you probably witnessed a glimpse of Cittàgazze. You can capture it in photograms with a special emulsion: https://hisdarkmaterials.fandom.com/wiki/Aurora?file=Citt%C3...

ComputerGuru3 days ago

Do you need long exposure to make it visible with a camera? How does that work in the presence of light pollution?

thebruce87m3 days ago

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.

ComputerGuru2 days ago

I tried it last night (generally cloudless sky). With the naked eye it just looked like light pollution. With long exposure it looked like a weirdly lit picture. In neither case did I see any hint of green or red.

I’m not in the city, but you’d have to actually be two states away to escape its light (literally not figuratively, according to dark sky maps).

:(

Macha3 days ago

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.

nbf_19953 days ago

Title says "S4" solar radiation event, but the linked page says "G4" geomagnetic storm

mrbluecoat2 days ago

Verizon will probably retroactively blame their outage on it.

wafflemaker2 days ago

What are the best apps to get notified when there's a geomagnetic storm /chances to see Aurora? Preferably not only for USA.

burnt-resistor3 days ago

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.

garbagewoman3 days ago

Not sure how to deal with this kind of wildly unbalanced risk assessment

_carbyau_3 days ago

Weirdly, while the site in question is "blaring klaxons!" there are more "cool night lights!" posts than concern.

zamadatix3 days ago

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).

pvab33 days ago

my Telecaster sure was noisy this morning but I didn't think much of it

guerrilla3 days ago

> 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.

rzzzt3 days ago
AnishLaddha3 days ago

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?

JoeDaDude3 days ago

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

aliljet3 days ago

I wonder if we're going to see an aurora over Seattle tonight?

throwway1203852 days ago

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.

cbeach3 days ago

Probably a stupid question, but should I unplug my EV? (UK)

_blk3 days ago

Yes! Absolutely, but only if you want to drive it.

qayxc3 days ago

No need. Wrong type of solar event. You might be able to see auroras, though. I saw some a couple of hours ago.

jacquesm3 days ago

No.

uticus3 days ago

Possible aurora visible through central US tonight

tigerlily3 days ago

Hopefully it's clear space weather for Artemis II coming up. I wonder what they do if it's inclement en route?

perihelions3 days ago

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...

xattt3 days ago

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.

JumpCrisscross2 days ago

Any aurora luck for those of us in the Rockies? (Near Yellowstone.)

zahlman3 days ago

It seems that the peak was several hours ago, and I haven't observed any effects from it...

guerrilla3 days ago

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.

_blk3 days ago

Nice. And it's somewhat relieving to read this over a Starlink connection.

ferguess_k3 days ago

Darn Montreal is still too south. Wish I were in Winnipeg.

brador2 days ago

What strength would destroy the sensor?

anon1153 days ago

any effects on the human body??

internet_points3 days ago

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.

tramtrist3 days ago

We never get aurora in Japan :(

pilaf3 days ago

Hokkaido got some back in November: https://www.asahi.com/ajw/articles/16155623

tramtrist2 days ago

Yeah I figure Hokkaido may get a taste but we here in Honshu never do :'(

johng2 days ago

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...

MORPHOICES2 days ago

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sparin93 days ago

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.

hindustanuday2 days ago

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yzydserd3 days ago

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