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  • Writer's pictureAlex Martin

Will a solar flare knock out the internet for months or years?

Updated: Jul 3

A solar prominence on the surface of the Sun
Solar prominence photographed by Alex Martin on June 9, 2023

by Alex Martin

Executive Director, Sidewalk Science Center

A recent report from a study that focused on data being gathered by NASA's sun-orbiting Parker Solar Probe (PSP) predictably led to a number of media outlets claiming that the Sun is about to release a giant explosion that will cause internet service to blackout for months or years. Source Source Source With this claim on the loose, a number of conspiracy theorists have also picked it up and are using this report as (unfounded) proof of a government conspiracy to control the population and destroy free speech. Source

As is often the case, these claims are blown wildly out of proportion through a misunderstanding of the Sun's cycle of activity, or through a deliberate misrepresentation of the information to sow fear within people who are not familiar with the impact solar activity has on Earth every day. On top of it all, these stories highlight the danger that pseudoscience, conspiracy, and pop culture's obsession with clickbait-heavy, fear-laden headlines can present to the integrity of scientific institutions and people working to translate and communicate news coming out of scientific fields.

The report described situations in which high energy, ionized particles carried by solar flares and storms could cause widespread failure of digital and electronic services, including access to the internet. Minor events of this nature already occur on a near-weekly basis (read below) during times of high solar activity.

NASA, however, never released a statement claiming the internet would go down for months. The phrasing being used for this particular claim seems to originate in this 2021 study conducted by computer scientists at the University of California, Irvine, who are studying solar wind data gathered by the PSP. While extreme solar storms are statistically possible (read below) the exaggeration we see today has been driven by numerous pop science and even more pop culture sites that demonstrate very little grasp of the knowledge of this subject. One site even ran with a headline that seems to imply the PSP was launched in June 2023, when in fact, in was launched at 3:31am EDT on August 12, 2018, nearly five years ago. While the article in question does mention the 2018 launch date, the headline is misleading.

How does the Sun impact the Earth?

The Sun is 1.4 million kilometers (865,000 miles) in diameter. It is not made of fire; rather, it's a massive sphere of hydrogen gas that is fusing into helium under intense heat and pressure. The helium fuses into carbon, and so on, and as the atoms are fused, they release energy in the forms of light and radiation.

On a basic level, we can confirm this by pointing a spectroscope at the Sun, a simple device that utilizes single-slit diffraction and prism refraction. Different elements absorb different wavelengths of color in the visible light spectrum. Looking at the Sun, you will see a rainbow with a series of black lines, the colors that have been absorbed by the elements present. Matching these patterns to the patterns of gas samples on Earth, we can accurately determine the elements present in the Sun, of which hydrogen accounts for about 75%.

A spectroscopy analysis of the Sun
Absorption lines in the spectrum of the Sun's light output: the black bars are wavelengths of light that have been absorbed by elements in the Sun's interior. Credit: N.A.Sharp, NOAO/NSO/Kitt Peak FTS/AURA/NSF

The Sun is not static: solar flares, sunspots, arcing prominences, solar tornadoes, and even a constant solar wind are all present on-and-off the surface. The Sun itself rotates on an axis just like everything else in the solar system. On average, a single "day" on the Sun lasts about 27 Earth days, depending on the latitude measured.

This dynamic motion, combined with the turbulence and uneven distribution of mass within the Sun, causes a regular cycle of activity that ultimately flips the Sun's net magnetic field. We call this period of magnetic flips a Solar Cycle. One Solar Cycle has a period of 11 years, with several years of higher-than-average activity, and several years of lower-than-average activity. 2014 marked the last solar maximum, the Sun's maximum activity for that cycle. 2019 marked the last solar minimum, with a transition period in 2020 before activity began increasing again. The next solar maximum is expected to peak in 2025.

With increasing activity, we observe a dynamic Sun: solar flares bursting into space every few days, prominences arcing over the surface, solar wind reaching greater velocities, black sunspots dotting the surface. With decreasing activity, we observe fewer flares, prominences, and sunspots, and a weaker solar wind.

Hydrogen-Alpha image of the Sun.
The Sun captured through a Hydrogen-Alpha spectrum telescope. Flares and prominences clearly jet out from the surface. Credit: Alex Martin

Solar flares are divided into classes dependent on their strength and size. Whenever a flare bursts off the Sun and crosses Earth's path, the Earth's magnetic field funnels the particles toward the north and south poles, ionizes the particles, and causes them to glow green, pink, red, blue, and sometimes purple. These are the Aurora Borealis and Aurora Australis: the Northern and Southern Lights.

With a weaker, smaller solar flare, the particles will remain closer to higher latitudes centered around the poles, and with a stronger, larger flare, the particles will be more spread out and visible at lower latitudes. The particles themselves are high energy, often releasing x-ray and gamma radiation. Most of this radiation is absorbed by Earth's magnetic field and atmosphere, but when it interacts with electrical and digitized technology, it causes a range of effects, from data corruption and flickering lights, to entire city power grid blackouts. In fact, on March 13, 1989, a powerful solar storm hit Earth and caused the millions of people in Canada's Quebec province to lose power for nearly 12 hours. Source Source

While millions of people losing power due to a solar storm is on the rarer side, a more common effect is called a radio blackout, where certain wavelengths of radio communications are disrupted for a period of minutes to hours. Cell phones, internet, radios, GPS, and other devices could briefly lose signal. Source Airplane communications are also disrupted, mostly during flights closer to Earth's poles, being at higher altitudes and thus more susceptible to impact from high energy particles. Source Satellites, being in space, have also been known to tumble out of control when solar flares disrupt their communications relays. Source

Can solar flares cause internet blackouts for months or years?

The last peak of solar maximum occurred in 2014. Reliance on digital technologies, while abundant and widespread, was still increasing. Today, nearly every aspect of our lives includes digitized technology in some way. Locally, smaller cell posts relay cell signals around town. Regionally, cell towers rise above forests and cities in order to establish line-of-sight relays between nearby towers. Across oceans, however, Earth's curvature is too great for line-of-sight towers, so most of the world's internet and communication is transmitted within fiberoptic undersea cables and amplifiers spanning every ocean, connecting entire continents.

Since 2014, the number of active satellites in space has increased from about 1,262 to more than 7,700 as of May 2023. While satellites don't necessarily contain the internet, a majority of them now transmit the internet, cellular communications, and radio and television. Satellites are also vital to monitoring Earth's surface. Source Source Source Source

The Sun's activity is actively increasing. Flares occur almost daily. You can visit the Solar Dynamics Observatory website to monitor the Sun in real-time. The Sun Today is also a good resource. An increase in activity inherently increases the probability of a larger solar event that could impact technology on and surrounding Earth. A solar storm of a magnitude that would shut down access to the internet and other communications for months or years is not likely to happen, but remains a statistical possibility. Solar flares already cause minor service outages and electrical blackouts on a regular basis.

Statistically speaking, yes, a months-long failure of that magnitude is possible. But it is not likely. Headlines making this claim will not adequately present the information necessary to understand how the Sun causes technology disruptions.

Can we prevent disruptions and blackouts caused by solar flares?

Light and heat travel from the surface of the Sun to Earth in an average of 8 minutes and 16 seconds, dependent on the Earth's distance from the Sun throughout the year. Earth's elliptical (noncircular) orbit brings it closest to the Sun in January (147 million kilometers/91.5 million miles) and farthest from the Sun in July (152 million kilometers/94.5 million miles).

On average, particles from the Sun take an average of 3-4 days to travel from the Sun to Earth. Light and heat are non-mass waves of energy, and so travel 1.1 billion kilometers per hour (669.6 million miles per hour). Coronal Mass Ejections (CMEs) and solar wind are physical particles, so travel at a much slower 1.6 million kilometers per hour (1 million miles per hour).

While the speed of light is too fast to give us time to act on any solar threats, having 72-96 hours to prepare for a solar storm erupting off the Sun is more reasonable to prepare for. Satellites can be rotated to protect electronic instruments, and power grids can briefly lower their output to prevent adverse surges that would lead to longer outages or permanent damage to equipment. Much of the technology we use today are also inherently safeguarded against magnetic and electronic failure: memory storage in smartphones and computers, for example, has transitioned to materials that are not affected by everyday magnetic fields. Source Developing resilience to adverse effects caused by the Sun's activity is fundamental to protecting digitization, satellites, cell tower relays, wireless communications, airplanes and rocketry, and other components that maintain the functionality of technology-based societies.

Communicating the risks and highlighting the measures being taken to provide that societal security is just as important to maintaining safe social order not built on fear and conspiracy, but on access to accurate and reliable information, and building a broad network of educators trained to properly translate and communicate that information to people who are not familiar with or unable to interpret it themselves.

Alex Martin is the Executive Director of Sidewalk Science Center. Learn more about him here.


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