Learn what a solar storm is, how solar flares and CMEs affect Earth, and whether geomagnetic storms can disrupt GPS, satellites, radio and power grids
The Sun is not a quiet ball of light. It is an active star that constantly releases energy, particles and magnetic fields into space. Occasionally, powerful eruptions from the Sun can disturb the space environment around Earth. These events are commonly referred to as solar storms.
Solar storms can produce beautiful auroras, but strong events can also affect satellites, radio communications, GPS systems, spacecraft and electrical infrastructure.
A major example occurred in May 2024, when a series of coronal mass ejections (CMEs) produced a powerful G5 geomagnetic storm, the strongest level on NOAA's geomagnetic storm scale. The event produced auroras across unusually large parts of the world and demonstrated why scientists continuously monitor the Sun.
So, what is a solar storm, how does it reach Earth, and what could happen during a powerful event? Let's explore the science behind space weather.
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| Coronal Mass Ejection (CME) and Earth |
What Is a Solar Storm?
A solar storm is a period of disturbed space weather caused by increased solar activity.
The Sun can release several types of eruptions, including:
Solar flares — powerful bursts of electromagnetic radiation.
Coronal mass ejections (CMEs) — huge clouds of magnetised plasma launched from the Sun.
Solar energetic particles — high-energy particles that can travel through space.
These phenomena are related to the Sun's magnetic activity but are not exactly the same thing.
When an Earth-directed CME reaches our planet, it can interact with Earth's magnetic field and trigger a geomagnetic storm.
This distinction is important:
Solar eruption → Space weather disturbance → Interaction with Earth's magnetosphere → Possible geomagnetic storm
What Causes Solar Storms?
The Sun has an extremely powerful and constantly changing magnetic field.
Magnetic fields on the Sun can become twisted, stressed and reorganised. When magnetic energy is suddenly released, it can produce a solar flare and, in some cases, a coronal mass ejection.
Solar activity follows an approximately 11-year cycle. During the more active part of the cycle, the Sun generally produces more sunspots and more space-weather events.
This active period is known as solar maximum.
What Is Solar Cycle 25?
The current solar cycle is known as Solar Cycle 25.
NASA and NOAA announced in October 2024 that the Sun had reached the solar maximum period of Cycle 25. Solar maximum does not mean that one enormous solar storm will occur on a particular day. Instead, it represents a period when solar activity is generally higher and powerful events become more common.
Even after solar maximum, significant solar activity can continue as the cycle gradually moves toward its next minimum.
The Major Solar Storm of May 2024
One of the most important recent examples of extreme space weather occurred in May 2024.
Between May 7 and May 11, the Sun produced multiple strong solar flares and several coronal mass ejections. The resulting geomagnetic storm reached G5, the highest category on NOAA's geomagnetic storm scale.
NASA reported that the storm produced spectacular auroras visible across many regions where such displays are unusual.
The event was also significant for space and technology operations because strong geomagnetic storms can affect satellites, radio communications, navigation systems and electrical infrastructure.
The May 2024 event provides an important real-world example of how solar activity can affect Earth.
How Does a Solar Storm Reach Earth?
The Sun is about 150 million kilometres from Earth, so solar material does not reach us instantly.
A solar flare produces electromagnetic radiation that travels at the speed of light and can affect Earth's ionosphere almost immediately after the radiation arrives.
A CME, on the other hand, is a massive cloud of plasma and magnetic field. Its travel time depends on its speed and direction.
When an Earth-directed CME reaches our planet, it interacts with the magnetosphere, the region dominated by Earth's magnetic field.
This interaction can produce a geomagnetic storm.
What Happens During a Geomagnetic Storm?
A strong geomagnetic storm can disturb Earth's magnetosphere and ionosphere.
According to NOAA, these disturbances can affect:
GPS and satellite navigation
High-frequency radio communication
Satellites
Electrical power systems
Aviation operations
Spacecraft
Satellite communications
The effects depend on the strength and characteristics of the space-weather event.
Not every solar eruption produces major problems on Earth. The direction, speed and magnetic properties of a CME are important factors in determining its impact.
Can a Solar Storm Affect the Internet?
One of the most searched questions about solar storms is whether they can cause an internet blackout or internet apocalypse.
The answer is more complicated than many sensational headlines suggest.
Solar storms can interfere with technologies that support communication and navigation. Strong space-weather events can disrupt radio communication, affect satellites and create disturbances in electrical systems.
However, it is not scientifically accurate to say that every major solar storm will simply switch off the entire global internet.
The potential impact depends on the strength of the storm and the infrastructure affected.
A particularly severe event could create significant technological disruptions, but the phrase “internet apocalypse” should be treated as a hypothetical extreme scenario rather than a guaranteed consequence of a solar storm.
How Do Solar Storms Affect GPS?
GPS signals travel between satellites and receivers through Earth's ionosphere.
Solar activity can disturb the ionosphere and change the way radio signals travel through it. This can reduce positioning accuracy or, during stronger disturbances, interfere significantly with navigation signals.
This matters because GPS and other satellite navigation systems are used in many areas, including:
Aviation
Shipping
Agriculture
Construction
Surveying
Transportation
Emergency services
Modern society depends heavily on accurate satellite navigation, which is one reason space-weather monitoring is important.
Can Solar Storms Damage Satellites?
Yes, strong space-weather events can create problems for satellites.
Energetic particles can affect spacecraft electronics and solar panels. Strong geomagnetic storms can also heat Earth's upper atmosphere, increasing atmospheric density at low altitudes.
This can increase atmospheric drag on satellites in low Earth orbit and change their orbits.
Satellite operators therefore monitor space weather and may take precautions when significant solar activity is expected.
Can Solar Storms Affect Power Grids?
Strong geomagnetic storms can induce electrical currents in long conductors on the ground.
This can affect electrical power transmission systems and other infrastructure.
One famous example occurred in March 1989, when a powerful geomagnetic storm contributed to a major power outage in Quebec, Canada.
Historical events demonstrate why monitoring and preparing for extreme space weather is important for modern electrical infrastructure.
Solar Storms and Radio Communication
Solar flares can produce strong bursts of X-rays and ultraviolet radiation.
When this radiation reaches Earth, it can disturb the ionosphere and interfere with high-frequency radio communication, particularly on the sunlit side of Earth.
These effects can be important for aviation, maritime operations and other users that depend on radio communication.
NOAA's space-weather monitoring systems provide alerts and forecasts to help organizations prepare for such conditions.
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| The beautiful 'Aurora Borealis', commonly known as the 'Northern Lights' |
The Beautiful Side of Solar Storms: Auroras
Solar storms are not only associated with technological disruption.
They can also create one of nature's most spectacular displays: the aurora.
When energetic particles interact with gases in Earth's upper atmosphere, those gases can emit light.
In the Northern Hemisphere, the phenomenon is called the aurora borealis, or northern lights.
In the Southern Hemisphere, it is called the aurora australis, or southern lights.
During powerful geomagnetic storms, auroras can become visible much farther from the polar regions than usual.
The May 2024 G5 geomagnetic storm produced an especially widespread auroral display.
Can Solar Storms Harm Astronauts?
Astronauts outside Earth's protective atmosphere and magnetic environment face greater exposure to space radiation.
Strong solar particle events can therefore present a significant radiation hazard to astronauts, particularly during missions beyond low Earth orbit.
This is one reason why understanding and forecasting space weather is important for future human spaceflight programmes, including India's Gaganyaan programme, and for future exploration of the Moon and Mars.
For astronauts aboard the International Space Station, Earth's magnetic field provides substantial protection, but space-weather conditions are still monitored carefully.
How Do Scientists Predict Solar Storms?
Scientists cannot predict every solar storm with perfect accuracy.
Instead, space-weather organizations continuously observe the Sun using spacecraft, telescopes and ground-based instruments.
Scientists monitor:
Sunspots
Solar flares
Coronal mass ejections
Solar wind
Magnetic fields
Solar energetic particles
When a potentially Earth-directed CME is detected, scientists can estimate its arrival time and possible effects.
NOAA's Space Weather Prediction Centre provides forecasts, watches and warnings for space-weather conditions.
Early warnings are particularly valuable because they allow satellite operators, power-grid operators, communication providers and other organizations to take precautions.
How Can We Prepare for a Severe Solar Storm?
Governments, space agencies and infrastructure operators monitor space weather and develop contingency plans.
Possible measures include:
Monitoring solar activity continuously
Protecting sensitive electrical equipment
Using backup communication systems
Preparing satellite operators for increased atmospheric drag
Adjusting satellite operations when necessary
Issuing warnings for aviation and radio users
Maintaining emergency power and communication capabilities
For most people, there is no reason to panic about ordinary solar activity. The important point is that modern technology requires continuous space-weather monitoring and preparation for rare extreme events.
Solar Storm vs Solar Flare vs CME
These terms are often used interchangeably, but they describe different phenomena.
Solar Flare
A solar flare is a sudden burst of electromagnetic radiation from the Sun.
Coronal Mass Ejection
A CME is a huge eruption of magnetised plasma from the Sun that can travel through interplanetary space.
Geomagnetic Storm
A geomagnetic storm occurs when solar-wind disturbances, often associated with a CME, strongly disturb Earth's magnetosphere.
Space Weather
Space weather is the broader term covering changes in the space environment caused by solar activity and their effects on Earth and technology.
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| Solar Flares Ejecting from the Corona |
Is Another Major Solar Storm Possible?
Yes. Solar activity is a natural and recurring phenomenon.
The end of Solar Cycle 25's solar maximum does not mean that powerful solar storms are impossible. Significant events can occur during different phases of the solar cycle.
Scientists continue to monitor the Sun because the exact timing and severity of individual eruptions cannot be predicted years in advance with certainty.
The lesson from events such as the May 2024 storm is not that a specific future “apocalypse” is inevitable. Rather, it demonstrates why understanding and preparing for extreme space weather matters.
Why Solar Storm Research Matters
Modern civilization depends heavily on technologies that operate in or through space.
Satellites support communication, navigation, weather forecasting, Earth observation and many other services.
A strong solar storm can temporarily disturb some of these systems.
That makes solar physics and space-weather research increasingly important as society becomes more dependent on satellite technology.
India and other spacefaring nations also need continuous monitoring of the Sun to protect spacecraft and support future human and robotic missions, with missions such as Aditya-L1 helping scientists study solar activity.
Conclusion
A solar storm is a natural consequence of the Sun's powerful and constantly changing magnetic activity.
Solar flares and coronal mass ejections can send energy and particles into space, and Earth-directed events can disturb our planet's magnetosphere.
The effects can range from spectacular auroras to disruptions affecting radio communication, GPS, satellites and electrical infrastructure.
The major geomagnetic storm of May 2024 showed that extreme space weather is not merely a theoretical possibility. At the same time, it also demonstrated the importance of scientific monitoring and forecasting.
Rather than focusing on predictions of an “internet apocalypse,” it is more useful to understand what solar storms actually are, how they affect modern technology and how scientists work to reduce their risks.
As humanity becomes increasingly dependent on satellites and prepares for longer missions into space, understanding space weather and solar storms will become even more important.
Frequently Asked Questions
1. What is a solar storm?
A solar storm is a period of disturbed space weather caused by increased solar activity. Solar flares and coronal mass ejections are among the phenomena that can contribute to significant space-weather events.
2. Can a solar storm hit Earth?
Yes. Earth-directed coronal mass ejections can interact with Earth's magnetic field and produce geomagnetic storms.
3. Was there a major solar storm in 2024?
Yes. A powerful G5 geomagnetic storm occurred in May 2024 after several coronal mass ejections reached Earth. It produced widespread auroras.
4. Can a solar storm destroy the Internet?
A severe solar storm can disrupt technologies that support communications, satellites, navigation and electrical infrastructure. However, a complete worldwide internet shutdown is not an inevitable consequence of a solar storm.
5. Can solar storms affect GPS?
Yes. Solar storms can disturb Earth's ionosphere and interfere with GPS and other satellite navigation signals, potentially reducing positioning accuracy.
6. Can solar storms damage satellites?
Strong space-weather events can affect satellite electronics and increase atmospheric drag on satellites in low Earth orbit.
7. What is a coronal mass ejection?
A coronal mass ejection, or CME, is a huge eruption of magnetised plasma from the Sun that travels through space.
8. What is solar maximum?
Solar maximum is the period of greatest solar activity within an approximately 11-year solar cycle. Solar Cycle 25 reached its solar maximum period in 2024.
9. Why do solar storms create auroras?
Energetic particles associated with solar activity interact with gases in Earth's upper atmosphere. This interaction produces the glowing displays known as auroras.
10. How do scientists monitor solar storms?
Scientists use space-based and ground-based instruments to monitor sunspots, solar flares, CMEs, solar wind and magnetic activity. Organizations such as NASA and NOAA use this information to study and forecast space weather.
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