Read Full StoryA solar flare is a sudden, intense burst of radiation from the Sun's surface, caused by the explosive release of magnetic energy.
A geomagnetic storm is a temporary disturbance of Earth's magnetic field caused by a surge of solar energy hitting the magnetosphere.
Just when everyone thinks the recent set of solar storm fizzles were all we were going to have this week, WHAM!
Region 4461 fires a massive blast and launches a fast moving solar storm towards Earth.
It carries the compressed wreckage of those earlier eruptions, tangled magnetic fields and turbulent plasma left behind like wakes in water.
The Sun has been restless all week. It has been flaring, erupting, and sending clouds of magnetised gas hurtling into the solar system one after another, like a city letting off fireworks it cannot stop.
Most of them missed. Some grazed past Earth's magnetosphere.
On the morning of June 6, 2026, it stopped grazing.
A patch of the solar surface called Active Region 4461 produced an explosion classified as an M1.8 flare, which sits in the mid-range of the solar flare scale.
Read Full Story
A solar flare is a sudden, intense burst of radiation from the Sun's surface, caused by the explosive release of magnetic energy.
And what this one carried was the thing that made space weather forecasters look twice.
A core filament, which was dense, magnetised, and fast. And headed directly for Earth.
That filament is now crossing the inner solar system at roughly 1,400 kilometres per second. It is expected to reach Earth on Monday, June 8, 2026.
The Space Weather Prediction Centre, or SWPC, the United States agency that watches the Sun around the clock, has issued a watch for a G3, or strong, geomagnetic storm.
A geomagnetic storm is a temporary disturbance of Earth's magnetic field caused by a surge of solar energy hitting the magnetosphere.
So I think my footage from last night has gone kinda viral
So many questions, here are a few answers...
It was taken at the Aurora Borealis Observatory on Senja in northern Norway.
It was taken on a @SonyAlpha 7sii, which is an amazing camera for astrovideography pic.twitter.com/D7Z30sO4AP— Matt Robinson (@Astromackem) November 23, 2020
Nasa is on alert. Aurora photographers are already setting their alarms.
WHAT IS A FILAMENT, AND WHY DOES IT MATTER?
Before science, visualise one image.
Imagine a bridge made not of steel or stone, but of electricity. It hangs over nothing, held up entirely by invisible magnetic fields, and inside it lives a river of gas that, by the standards of the surrounding environment, is remarkably cold and remarkably dense.
That is a filament.
The Sun's outer atmosphere, called the corona, is threaded with enormous invisible magnetic fields that arc out from the solar surface in loops.
These fields can trap dense plasma, which is ionised gas, in a suspended structure that should not, by any intuitive logic, be able to stay in place. And for a time, it does.
The plasma inside a filament sits at around 5,000 to 10,000 degrees Celsius. That sounds scorching until you learn that the corona surrounding it burns at roughly one to two million degrees. A filament is, by solar standards, cold. And heavy.
When the magnetic cage holding it becomes unstable, the filament erupts outward, dragging its dense plasma and powerful, trapped magnetic fields into space.
A denser eruption travels faster, hits harder, and, crucially for anyone watching the sky on Monday night, drives a more intense geomagnetic storm.
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Space weather scientist Tamitha Skov, who identified this event from satellite imagery, called it a textbook core filament eruption and told aurora photographers to get ready for June 8.
She was not being dramatic. She was being precise.
THE SHAPE THAT STORES THE FURY
Active Region 4461 had what solar physicists call a sigmoidal configuration. Its magnetic field lines were wound into an S-shape, like a spring twisted far past the point at which it should naturally rest.
The more twisted a magnetic structure becomes, the more energy it stores, and the more violently it releases that energy when it finally gives way.
When the filament erupted, those field lines snapped and reconnected in a process called magnetic reconnection.
Think of two rubber bands, both stretched beyond their limit, cut at the same moment. All of that stored tension, released at once.
That released energy did two things simultaneously. It produced the X-ray flare recorded at peak intensity around 13:40 UTC, which is 7:10 PM IST on June 6.
Incredible aurora timelapse filmed in Fort Yukon, Alaska.
: Vincent Ledvinapic.twitter.com/hSRFSJJ0wL— Wonder of Science (@wonderofscience) December 28, 2023
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An X-ray flare is a burst of X-ray radiation released by the Sun during a solar explosion, powerful enough to disrupt radio communications on Earth.
The filament eruption also launched a billion-tonne cloud of magnetised plasma into space at over 1,400 km per second, the cloud that is now on its way to Earth, carrying with it the conditions for the most vivid auroral display of the week.
THE SINGLE VARIABLE THAT DECIDES HOW BRIGHT AURORAS WILL BE
When this cloud reaches Earth, it will not strike the surface. Earth's magnetic field, called the magnetosphere, acts as a continuous shield.
But whether it holds depends on one measurement forecasters cannot take until the cloud is almost here.
Inside every such ejection is an embedded magnetic field. If its southward-pointing component, known as Bz, is oriented southward on arrival, it aligns opposite to Earth's own field.
When opposite fields meet, they reconnect. The shield opens. Solar energy pours in. And the auroras begin.
Just when everyone thinks the recent set of solar storm fizzles were all we were going to have this week, WHAM! Region 4461 fires a massive blast and launches a fast moving solar storm towards Earth. Looking closely at the region just before the eruption, a very dense core pic.twitter.com/DQjOWZANVG— Dr. Tamitha Skov (@TamithaSkov) June 7, 2026
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The longer and more strongly Bz points southward, the more energy enters, the more severe the storm, and the further south the auroras travel.
The severity of a geomagnetic storm is measured on a scale of G1 to G5, where G1 is minor and G5 is extreme, the kind that knocked out power grids and sent auroras blazing across India in May 2024.
This storm is forecast at G3, classified as strong, with brief G4, or severe, periods possible if conditions align unfavourably.
At G3 and above, auroras shift from the polar regions toward much lower latitudes.
Parts of northern India, central Europe, the northern United States, and southern Australia and New Zealand could see displays painting the sky in greens, purples, and reds, provided skies are dark and clear on Monday night.
Even a G3 is enough to push the auroral oval significantly southward. A G4 period would push it further still.
THE QUESTION THE SUN HAS NOT ANSWERED YET
This week has already been a busy one. Active Region 4455, a different region, fired multiple flares and produced G2-level storms around June 3.
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The solar wind is not calm. It carries the compressed wreckage of those earlier eruptions, tangled magnetic fields and turbulent plasma left behind like wakes in water.
An aurora lighting up the night sky over Zhongshan Station in Antarctica captured with a spectacular timelapse.pic.twitter.com/LX5j1nYfCI— Wonder of Science (@wonderofscience) March 16, 2023
When a fast ejection overtakes a slower one, the result is called a cannibal CME. The two clouds merge into one denser, more powerful mass, potentially intensifying the storm further on arrival.
Monday's arrival could trigger exactly this kind of interaction.
The Bz direction, the single variable that determines whether Monday night's sky lights up or stays dark, will only be measured when the cloud crosses monitoring satellites roughly 1.5 million kilometres from Earth. That gives 15 to 60 minutes of warning.
Until then, the aurora hunters wait. The forecasters watch. And the Sun, as it always does, keeps its answer to itself.
- Ends
