This 1940 solar storm was so severe it made metal wires crackle; Know all about this ‘Sunspot tornado’

In March 1940, a solar storm struck the Earth that was so intense that it made metal wires crackle and disrupted phone lines and telegraph services for 5 hours. Know the impact of the Sunspot tornado.

| Updated on: Aug 11 2023, 16:15 IST
Do all solar activities like solar storms, CME, impact Earth? This is what NASA says
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1/5 Sun is a source of energy and a lot of activities keep on happening on the fireball. But can Earth be impacted by solar activities? Before we tell you that, it is important to know what solar activity is? According to NASA, solar flares, coronal mass ejections, high-speed solar wind, and solar energetic particles are all forms of solar activity. All solar activity is driven by the solar magnetic field. (NASA)
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2/5 Solar flares impact Earth only when they occur on the side of the sun facing Earth. Because flares are made of photons, they travel out directly from the flare site, so if we can see the flare, we can be impacted by it. (Pixabay)
Solar Storm
3/5 Coronal mass ejections, also called CMEs, are large clouds of plasma and magnetic field that erupt from the sun. These clouds can erupt in any direction, and then continue on in that direction, plowing right through the solar wind. Only when the cloud is aimed at Earth will the CME hit Earth and therefore cause impacts. (NASA)
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4/5 High-speed solar wind streams come from areas on the sun known as coronal holes. These holes can form anywhere on the sun and usually, only when they are closer to the solar equator, do the winds they produce impact Earth. (NASA)
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5/5 Solar energetic particles are high-energy charged particles, primarily thought to be released by shocks formed at the front of coronal mass ejections and solar flares. When a CME cloud plows through the solar wind, high velocity solar energetic particles can be produced and because they are charged, they must follow the magnetic field lines that pervade the space between the Sun and the Earth. Therefore, only the charged particles that follow magnetic field lines that intersect the Earth will result in impacts. (NASA)
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Know all about the devastating 1940 solar storm. (Pixabay)

The most recent example of a solar storm that caused damage to Earth's infrastructure was in February 2022 when some of the Starlink satellites launched by SpaceX were trapped in the drag caused by the energized particles in the upper atmosphere, and crashed. However, it is nothing in comparison to the storm that struck the Earth in March 1940. This solar storm was so powerful that it made metal wires crackle due to excessive static electricity and disrupted phone lines and telegraph services for 5 hours. The New York Times called it a ‘Sunspot tornado', and it remains as an example of what can happen when a solar storm really shows its wrath. Let us take a look. 

According to a report by, “On March 24, 1940, a solar storm hit Earth so hard it made copper wires in the United States crackle with 800 volts of electricity. A New York Times headline declared that a "sunspot tornado" had arrived, playing havoc with any signal that had to travel through metal wires”. The report also attached a newspaper article from that day which highlighted that shortwave communication, police and press teletypes were also affected during the story. 

The terrifying solar storm of 1940

This storm was so extreme that for the few hours it was active, it blocked all forms of long-distance communication. Further, it was reported that more than a million telephones and teletypes were affected during the storm. In fact, the accumulation of static charge was so high near the surface level that copper and other metal wires began crackling due to its impact.

Such a storm, today, would damage large satellites, disrupt GPS and mobile networks, impact power grids, and even affect ground-based electronics. 

A question that arises is if this storm was so powerful, how come we don't hear about it as much as we do about the Carrington event or the Halloween solar storm? The answer has to do with history. In 1940, theWorld War II was going on and the US was about to jump into action. So, it is no surprise that a minor inconvenience like that was not on people's minds. 

And if you think such a solar storm cannot occur today, you would be mistaken. Just this year, we have seen two CME clouds that carried enough charge within it to spark a similar storm. But luckily, neither of them was Earth-directed. 

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First Published Date: 11 Aug, 15:57 IST