A History of Havoc: The Most Disruptive Solar Storms and Their Consequences


Solar storms, also known as geomagnetic storms, are disturbances in the Earth’s magnetosphere caused by solar wind and coronal mass ejections (CMEs) from the Sun. These events have the potential to disrupt communication systems, satellite operations, and power grids, causing widespread societal impacts. This article reviews some of the worst solar storms in history and the consequences they brought.

The Carrington Event (1859)

Drawing of a sunspot by Richard Carrington
Source: Wikipedia

The Carrington Event is the most powerful solar storm ever recorded. It occurred between August 28 and September 2, 1859, and was named after British astronomer Richard Carrington, who observed the solar flare that caused the storm. This geomagnetic storm resulted in widespread auroras, telegraph systems being disrupted and, in some cases, catching fire.


While the world was not as technologically dependent in 1859, the Carrington Event still caused significant disruptions to the telegraph system, which was the primary means of communication at the time. If a similar event were to occur today, the consequences would be much more severe, potentially causing trillions of dollars in damages and requiring years to recover.

The Railroad Storm (1921)

The 1921 Railroad Storm, also known as the New York Railroad Storm, was a powerful solar storm that occurred on May 13-15, 1921. The storm was characterized by intense auroras visible as far south as Puerto Rico and Samoa, as well as significant disruption to telegraph and radio communications. The event got its name due to its impact on the railroad industry, as it caused widespread voltage surges and fires in telegraph equipment, which was critical to railroad operations at the time.


The 1921 Railroad Storm showcased the vulnerability of early electrical and communication systems to solar storms. Telegraph lines and equipment, which were the primary means of long-distance communication in the early 20th century, were severely affected by the geomagnetically induced currents (GICs) produced by the storm. Telegraph operators reported receiving electric shocks, and some telegraph offices even caught fire due to the intense electrical currents.

The storm also disrupted radio communications, which were in their infancy in 1921. Radio signals were significantly degraded or completely blocked during the storm, hampering communication and navigation for ships at sea and early aviation.

Although power grids were not as extensive or interconnected as they are today, the 1921 Railroad Storm did cause voltage fluctuations and equipment damage in some areas. This event served as an early indication of the potential threat solar storms pose to electrical infrastructure.

The 1972 Solar Flare (1972)

On August 4, 1972, a powerful solar flare erupted from the Sun, followed by a CME that led to a significant geomagnetic storm. This event, known as the 1972 Solar Flare, had substantial effects on Earth’s magnetosphere and caused noticeable disruptions to communication systems.


One of the most notable impacts of the 1972 Solar Flare was the disruption of AT&T’s long-distance telephone system. At the time, AT&T utilized microwave relay stations to transmit long-distance telephone calls across the United States. The geomagnetic storm induced strong electrical currents in the Earth’s atmosphere, which interfered with the microwave signals and caused widespread telephone outages.

The event led AT&T to invest in research on space weather and its effects on communication systems. The company collaborated with NASA and other organizations to develop better space weather monitoring and forecasting capabilities. The 1972 Solar Flare also played a role in motivating the development of fiber-optic communication networks, which are less susceptible to space weather disruptions compared to microwave relay systems.

Additionally, the 1972 Solar Flare had impacts beyond communication systems. The storm caused significant auroras, which were visible as far south as Texas, and disrupted navigation systems, such as LORAN, used by maritime and aviation industries. Furthermore, it was reported that the event caused the detonation of numerous U.S. Navy sea mines in the waters off the coast of North Vietnam, as the storm’s induced currents triggered their magnetic sensors.

The Quebec Blackout (1989)

On March 13, 1989, a severe geomagnetic storm caused the Hydro-Qu├ębec power grid to collapse, leaving millions of people in Quebec, Canada without power for up to nine hours. This storm was the result of a powerful CME that impacted the Earth’s magnetosphere.


The Quebec Blackout demonstrated the vulnerability of modern power grids to solar storms. It caused widespread economic and social disruptions and cost hundreds of millions of dollars in damages. The event led to increased research and investment in space weather forecasting and the development of protective measures for power grids.

The Bastille Day Event (2000)

The 2000 Bastille Day Event refers to a powerful solar storm that occurred on July 14, 2000. This event was named after the French national holiday, as it took place on the same day. The storm was caused by an X5-class solar flare, one of the strongest solar flares ever recorded, which was accompanied by a fast-moving CME that impacted the Earth’s magnetosphere.


The Bastille Day Event had several significant effects on Earth’s space environment and technology. The storm caused strong auroras, visible as far south as Texas and the Mediterranean, and induced geomagnetically induced currents (GICs) that affected power grids and communication systems.

One of the most notable impacts was the temporary loss of contact with the Advanced Composition Explorer (ACE) satellite, which provides real-time solar wind data crucial for space weather forecasting. Additionally, the storm disrupted the operation of the Solar and Heliospheric Observatory (SOHO) satellite, which monitors solar activity and provides data for space weather predictions.

The Bastille Day Event also affected the Global Positioning System (GPS), causing degradation in its accuracy and reliability. This disruption highlighted the vulnerability of satellite navigation systems to solar storms and emphasized the importance of developing backup navigation technologies.

Furthermore, the storm caused several other satellites to experience anomalies or temporary failures, including those used for communication and weather monitoring. Some high-frequency (HF) radio communication systems, particularly those used by airlines for transpolar flights, were disrupted, leading to temporary changes in flight routes to ensure continuous communication.

The Halloween Storms (2003)

Between October 19 and November 7, 2003, a series of powerful solar storms, collectively known as the Halloween Storms, wreaked havoc on Earth’s magnetosphere. These storms resulted in intense auroras, satellite malfunctions, and disruptions to power grids and communication systems.


The Halloween Storms highlighted the potential for solar storms to cause significant disruptions to modern society. Satellite navigation and communication systems were disrupted, and several satellites experienced malfunctions or were permanently damaged. Power grids in North America and Europe experienced voltage fluctuations, and a power outage occurred in Sweden. The storms also caused airlines to reroute flights due to concerns about increased radiation exposure to passengers and crew.

The 2006 Solar Flare (2006)

On December 5, 2006, a powerful X9-class solar flare erupted from the Sun, making it one of the most intense solar flares observed in recent years. This flare was accompanied by a CME that caused a geomagnetic storm on Earth, with noticeable effects on our planet’s space environment and technological systems.


The 2006 Solar Flare had several significant consequences on Earth’s technology and infrastructure. One of the primary effects was the disruption of high-frequency (HF) radio communications, which are heavily relied upon by aviation, maritime, and emergency response services. The ionospheric disturbances caused by the solar flare led to the degradation or loss of HF radio signals, resulting in temporary communication disruptions.

Additionally, the flare and associated geomagnetic storm affected satellite operations. Several satellites experienced anomalies or malfunctions, including the Galaxy 15 satellite, which suffered a temporary loss of contact. The storm also increased the risk of satellite collisions due to increased atmospheric drag, which can alter satellite orbits.

The 2006 Solar Flare further impacted the Global Positioning System (GPS), causing short-lived degradation in its accuracy and reliability. This event highlighted the vulnerability of satellite navigation systems to space weather and the importance of developing backup navigation technologies.

The geomagnetic storm also caused fluctuations in power grids, with some regions experiencing voltage irregularities. Although no widespread blackouts occurred as a result of the storm, it served as a reminder of the potential threat solar storms pose to electrical infrastructure.


The history of solar storms offers a stark reminder of the potential consequences of severe space weather events. While our technological advancements have made life more comfortable and convenient, they have also made us more vulnerable to the impacts of solar storms. It is essential to continue investing in space weather research, monitoring, and forecasting to better understand and prepare for these potentially catastrophic events.