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?
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.
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.
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
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.
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.
> 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?
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.
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!
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...
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.
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.
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.
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?
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)
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.
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.
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?
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.
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.
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.)
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.
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.
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.
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.
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.
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.
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.
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.
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.
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?
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).
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.
> "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."
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.
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.
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.
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.
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.
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.
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.
[0]: https://en.wikipedia.org/wiki/Solar_cycle
G5: " Pipeline currents can reach hundreds of amps, HF (high frequency) radio propagation may be impossible in many areas for one to two days..."
Now I'm feelin' so fly like a G6
https://www.youtube.com/watch?v=DWRJC8ap9B4
Looks like G5 is the highest level and the scale system is used by NOAA.
Though I suppose you could also queue it.
It’s also technically not a documentary but historical drama.
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
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.
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
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?
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...
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.
https://www.foto-webcam.eu/webcam/kleinfleisskees/
https://www.foto-webcam.eu/
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
- 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!
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.
What if one of my homelabs needed 100% uptime to meet my wife's SLA for messaging? Is this able to be protected?
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.
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...
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.)
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.
I've posted on this before, for other warnings. Not going to repeat that.
https://emergencyprocedures.pjm.com/ep/pages/dashboard.jsf
/s
What is useful is KAus and the G index, KAus is shown on this page, so thats what i'll be tracking.
G4 storms are ~100 per solar cycle (~11 years).
So roughly 9 G4 events/year on average.
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.
Please stop watching that guy, he is a total fraud and knows nothing about physics.
Sooo much jargon.
Flux and bZ!
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?
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.
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.
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
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.
hypothetical: if a carrington event-esque storm happens during the mission, how badly will the houston <-> orion module communication links be affected?
No, it isn't. It clearly says everything is under control but it would be good to keep an eye on it.
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...
My mind goes to the working mechanism of eidophor projectors, where oil on the projection bowl does indeed deform under electron beam exposure.
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.
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.
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.