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Solar Storms: Exploring the Sun's Explosive Outbursts

Close up of the Sun’s surface

Close up of the Sun’s surface (DrPixel, Getty Images)

Close up of the Sun’s surface

Close up of the Sun’s surface (DrPixel, Getty Images)


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Learn about solar storms and how they impact Earth.

Did you know that space experiences weather? This is known as space weather. Earth's weather involves conditions like temperature and humidity. Space weather involves radiation, charged particles and solar wind. These cause powerful storms. The storms are called solar storms or space weather storms.

Solar storms release bursts of high-energy particles and electromagnetic radiation. These can create colourful patterns in the sky above Earth. They can also impact satellites. In this backgrounder, we'll explore the science of solar storms, their causes, and how scientists predict and understand space weather.

What is a solar storm?

A solar storm is a disturbance on the surface of the Sun. These storms can take the form of large explosions called solar flares. Or they can be bursts of plasma called coronal mass ejections, or CMEs.

Let’s take a closer look at these two types of storms.

Types of Solar Storms

Solar Flares

Solar flares are like fireworks from the Sun. They are massive explosions of electromagnetic radiation that happen on the Sun's surface.

The surface of the Sun is covered in a web of magnetic fields. Sometimes these magnetic fields can get twisted and tangled up, like rubber bands wound too tightly. When this magnetic tension builds up, it can suddenly untangle. This releases a burst of energy in the form of a solar flare.

The radiation released in solar flares can range across the electromagnetic spectrum from radio waves to x-rays and gamma rays. These can look like a sudden, intense burst of light and last for a few minutes, or even hours.

Shown is a colour photograph of a glowing red loop stretching out from the Sun’s surface.
Solar flares on the surface of the Sun (Source: Digital Vision via Getty Images).
Image - Text Version

Shown is a colour photograph of a glowing red loop stretching out from the Sun’s surface. The Sun looks like a sphere of mottled red, orange and black, glowing from within. On the top left, a huge loop of material stretches out into space and back down to the Sun’s surface. It looks like twisted, red, translucent liquid.

Types of Solar Flares 

Scientists classify solar flares into four categories. These are based on their x-ray brightness. The categories are: X-class, M-class, C-class and B-class. Each category has its own characteristics and effects on Earth.

Category Effects
B-Class: Very Small Ones
  • Its radiation is not detectable from Earth
  • There are no detectable effects on Earth
C-Class: Small Ones
  • There is a minor release of radiation
  • They don’t usually cause effects on Earth
M-Class: Medium-Sized Ones
  • There is a significant release of radiation
  • They can trigger:
    • Brief radio blackouts
    • Minor disruption of satellites
    • Auroras
X-Class: Big Ones
  • These are major events that release a tremendous amount of radiation.
  • They can have a big impact on earth. They can trigger:
    • Global radio blackouts
    • Disruption of satellites

Coronal Mass Ejections (CMEs)

Coronal Mass Ejections are not your everyday solar events. They are massive expulsions of plasma and magnetic fields that shoot out from the Sun’s corona.

CMEs occur because of disturbances in the Sun’s magnetic field. Most CMEs form near sunspots, which are cooler and darker areas on the Sun's surface.

CMEs travel out from the Sun at very high speeds. The slowest CME’s are less than 250 kilometres per second (km/s). The fastest are nearly 3 000 km/s. This means that the fastest CMEs can reach Earth in just 15-18 hours!

NASA | Magnificent Eruption in Full HD (2:10) from NASA

Shown is a colour photograph of a burst of bright yellow from the surface of the Sun.
Large coronal mass ejection erupts on the Sun (Source: Stocktrek Images via Getty Images).
Image - Text Version

Shown is a colour photograph of a burst of bright yellow from the surface of the Sun. The sphere of the Sun takes up most of the photograph. Its surface glows in mottled red, orange and yellow. In a few spots, bright yellowish-white streaks travel outwards from the surface. Above these, bursts of wispy yellow can be seen against the blackness of space.

CMEs are so intense that they can pose some serious challenges for space activities. The radiation storms within CMEs can be hazardous to spacecraft and astronauts.

Did you know?

In 2022, NASA's Parker Solar Probe became the first spacecraft to fly through a Coronal Mass Ejection (CME). Parker was about to make its 13th close approach to the Sun when a CME erupted right in front of it. Check out the video footage here.

How do solar storms impact Earth? 

So why don’t we feel the direct impact of solar storms? Earth's magnetic field protects us from their harmful effects. The magnetic field creates a protective bubble around the planet we call the magnetosphere. It deflects and redirects harmful particles away from the Earth.

Did you know?

Scientists can recreate the protection of the earth’s magnetic field by making a Faraday cage. These are protective enclosures that prevent electromagnetic radiation from entering them. Learn how to make your own Faraday cage here.

Even though we don’t get hit with the full impact of solar storms, they are still noticeable. When solar storms interact with the Earth’s magnetic field, it can cause disturbances in the field. Scientists call these Geomagnetic storms.

Geomagnetic storms can affect our planet in some fascinating and challenging ways. For example, when a CME collides with Earth's magnetic shield, the impact can send a burst of particle radiation into Earth's upper atmosphere. If the particles interact with the gas molecules in Earth’s thermosphere, they can light up. These excited gas molecules create mesmerising light shows we call auroras

Shown is a colour infographic with a variety of objects impacted by space weather.
Impacts of space weather (Source: Public domain image by the US National Weather Service).
Image - Text Version

Shown is a colour infographic with a variety of objects impacted by space weather. The Sun is a yellow quarter circle at the top left. Beyond the Sun, the blackness of space fades to dark blue. There are many stars in the light blue area. Earth is a dark blue quarter circle at the bottom right. Bright blue around its edge represents our atmosphere. Several objects appear to float in space above Earth. From left to right these include an astronaut in a space suit, labelled “Human Space Exploration”, a metal cylinder with two solar panels attached labelled “Satellites”; a thick squiggle of green and purple above the northern hemisphere labelled “Aurora (Northern Lights)”; an airplane labelled “Aviation”; a pale blue radio tower labelled “Communications”; and a lightbulb labelled “Electric Power.”

Impacts on Technology

Geomagnetic storms can impact technology, like Earth’s communication systems. You might have experienced static or interference on your radio during a thunderstorm. In a similar way, the increased electromagnetic activity during a geomagnetic storm can interfere with radio waves. This interference can disrupt long-distance communication, such as those used in aviation.

Geomagnetic storms also impact satellites. Many satellites orbiting the Earth are important for weather forecasting, global positioning systems (GPS), and communication. The increased radiation and charged particles can damage or disrupt satellite operations.

Shown is a colour illustration of Earth surrounded by a web of orbiting satellites.
Global satellite network around the Earth (Source: Mark Garlick/Science Photo Library via Getty Images).
Image - Text Version

Shown is a colour illustration of Earth surrounded by a web of orbiting satellites. The curve of Earth sweeps across black space. Above the surface, a web of faint blue lines criss-cross like a lattice. Seven tiny satellites travel along some of these lines. The part of the Earth in the foreground is in shadow and the part of the Earth in the background is brightly lit.

Scientists use a scale they call the Geomagnetic Storm G-Scale, to rank storms. This is based on how disruptive they are. Storms are ranked from G1-G5. G1 storms cause minor disruptions and G5 storms cause severe disruptions. 

Predicting solar storms

So how do scientists predict solar storms? The Canadian Space Weather Forecast Centre and the Space Weather Prediction Centre are North American organisations that track, analyze, and forecast space weather. The scientists at these centres use ground-based instruments and satellites to observe the Sun for any changes or activity such as solar flares or CMEs.

Instruments like Nasa’s Advanced Composition Explorer (ACE) orbit 1.5 million kilometres above the Earth. It provides important information to scientists who study patterns and clues to generate space weather forecasts.

Did you know?

You can check the space weather forecast just like you can check the weather on Earth!

Solar storms are extraordinary space weather events. They can have a big impact on our world. Scientists play an important role by studying the effects of these events and how to predict them. 

Geomagnetic storms and solar flares, explained (2022)
This video (2:58 min.) from USA Today explores how solar storms cause geomagnetic storms and the impacts these storms can have on earth.

Explained: What is a Solar Storm? (2023)
This video from Business Standard (3:08 min.) explores solar storms, how they develop, and their impacts.

Sun | NASA Space Place – NASA Science for Kids
This webpage from NASA provides activities, articles and videos to help learn about the sun.

What is a Faraday Cage? (2023)
This video from Radwell International (1:16 min.) explores what a faraday cage is, how it is built and how to test one.


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