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What Is St. Elmo's Fire?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

St. Elmo's Fire is a weather phenomenon that has attracted attention and comment for hundreds of years. This phenomenon manifests in electrical storms and other weather conditions that generate atmospheric electric fields. When conditions are right, a glowing blue to green light can appear around things like lightning rods, pipes, and the masts of ship. While St. Elmo's Fire looks like a fire, it is in fact plasma, gas that has been ionized due to the presence of an extremely large electrical field. Once the charge dissipates, after a few seconds or minutes, the light vanishes along with it.

Many people have actually seen St. Elmo's Fire, but they might not have realized it. Neon lights are a carefully contained and controlled form caused by turning gases into plasma. Neon lights come in a range of colors, depending on the gases enclosed in the tubes; the mixture of gases in the Earth's atmosphere is what causes the natural phenomenon to appear green to blue in color.

Woman with hand on her hip
Woman with hand on her hip

This interesting weather event is named for the patron saint of sailors, Saint Erasmas of Formiae, also known as St. Elmo. Sailors often witnessed St. Elmo's fire on their journeys, and superstitions came to be attached to the mysterious glowing plasma; many sailors felt that its presence was a sign that the saint was looking after them. St. Elmo's Fire can also appear on land, tending to concentrate around pointed objects which concentrate electrical charges.

For the phenomenon to manifest, a grounded object must discharge electricity in a charged atmospheric field. The electricity from the grounded object ionizes the surrounding air, pulling the molecules in the air apart and creating what is known as a corona discharge, a prolonged electrical spark which causes a momentary bright flash. Storms are ideal for creating St. Elmo's Fire because they tend to generate charge differences, creating the circumstances necessary for the corona discharge.

If a person is close enough to St. Elmo's Fire, he or she can hear it buzz or hiss sometimes. Because the corona discharge is simply glowing plasma, rather than an actual fire, it will not cause objects around it to catch fire, and sometimes the light can be coaxed into doing tricks. Airline pilots, for example, have written about playing with it when it gathers outside their windows, trailing their fingers across the windshield to attract the plasma.

Documented Eyewitness Accounts of St. Elmo’s Fire

The earliest recordings of St. Elmo’s Fire were from the ancient Greeks, who described the distinctive lights and named them after mythological figures. After the Greeks, sailors and scientists throughout the world also reported their encounters with the natural occurrence. Centuries of these documented accounts reveal both astonishment and fear of observers.

Early Sightings at Sea

Sailors from various nations created names for St. Elmo’s Fire. Welsh seamen called the mystifying flares “spirit candles,” “candles of St. David” or “candles of the Holy Ghost.” Likewise, Russian sailors called the fascinating lights “Saint Nicholas” or “Saint Peter’s Lights.” In Portugal, seafarers used the term corposant, meaning “holy body.” This resulted in references to corposants by subsequent scholars. For example, Pliny the Elder wrote about corposants in “Naturalis Historia” (Natural History). Julius Caesar also mentioned corposants in “De Bello Africo.”

Observations by Scientists

Charles Darwin witnessed St. Elmo’s Fire when sailing on the Beagle in 1832. While anchored in the Rio de la Plata, he wrote in his diary: “Everything is in flames — the sky with lightning, the water with luminous particles and even the very masts are pointed with a blue flame.”

In 1899, Nikola Tesla created St. Elmo’s Fire in his Colorado laboratory. While he was testing one of his Tesla coils, the room became electrified, causing butterflies to emit the blue sparks indicative of the phenomenon.

References to St. Elmo’s Fire in Literature

Numerous literary descriptions of St. Elmo’s Fire include both negative and positive associations. Here are a few examples.

St. Elmo’s Fire As an Ominous Sign

Some references to St. Elmo’s Fire suggest the weather-induced wonder is a bad omen. In Act 1, Scene 2 of Shakespeare’s “The Tempest,” Prospero commands the spirit Ariel to create a tempest to harm his enemies at sea. Although hesitant, Ariel relents, casting St. Elmo’s Fire on the ship’s mast. The frightened passengers jump into the ocean and swim for their lives. In Samuel Taylor Coleridge’s “The Rime of the Ancient Mariner,” the ominous natural phenomenon is called “death fires,” and the seawater below “burnt green and blue and white.”

Gothic novels of the 18th and 19th centuries declared St. Elmo’s Fire a sign of divine judgment. In Ann Radcliffe’s “The Mysteries of Udolpho,” published in 1794, Emily asks the watchman about the darting light on his lance. He tells her another guard believes it is an omen “and bodes no good.”

St. Elmo’s Fire As a Symbol of Mercy and Hope

Other literary pieces attribute the lights of St. Elmo to God’s mercy and a foreseeable end to storms. An early reference is from the epic poem “Orlando Furioso,” written in 1516 by Ludovico Ariosto. After a punishing three days of storms, St. Elmo’s Fire emerges on the bow of a tattered ship: “But now St. Elmo’s Fire appeared, which they had so longed for…and gave them hope of calmer airs.”

“Moby Dick,” Herman Melville’s novel published in 1851, describes Ahab’s enchantment and relief as the corposants hover around the ship’s three masts. Starbuck, however, believes the white flames are God’s warning to end the pursuit of Moby Dick.

St. Elmo’s Fire Shouldn’t Be Feared

A weather phenomenon resembling lightning may seem harmful, but St. Elmo’s Fire is not. Unlike lightning, it doesn’t strike golf courses, trees or people, and it won’t cause fires or burning. A buzzing or crackling sound occurs when it appears, but without the accompanying electrical shock. St. Elmo’s Fire on its own is not dangerous; however, it is often a precursor to hazardous natural events such as thunderstorms and volcanic eruptions.

Besides sea and land events, St. Elmo’s Fire also appears in the air. In June 1982, the crew and passengers of British Airways Flight 9 witnessed long flashes of light flickering from the front of the aircraft. More recently, pilots posted videos capturing their encounters with the unique weather condition in the cockpit. In October 2020, the Royal Air Force’s 99 Squadron posted footage on Twitter of the plasma lights flickering across the nose of a C17. The video’s caption reassured viewers not to fear the event: “The electrical weather phenomenon of St. Elmo’s Fire isn’t dangerous, but it usually means you’re surrounded by storms!”

Although St. Elmo’s Fire is considered a rare occurrence, centuries of witness testimony from the sea, land and air indicate it is not a safety threat. Rather, it’s a natural marvel bound to fascinate those who are fortunate enough to see it.

Frequently Asked Questions

What exactly is St. Elmo's Fire?

St. Elmo's Fire is a weather phenomenon involving a luminous plasma created by a corona discharge from a sharp or pointed object in a strong electric field in the atmosphere, such as those generated by thunderstorms or volcanic eruptions. It's named after St. Erasmus of Formia (St. Elmo), the patron saint of sailors, who considered it a good omen.

How does St. Elmo's Fire occur?

St. Elmo's Fire occurs when the electric field around an object is strong enough to ionize the air around it, leading to a sustained glow due to the discharge of electricity from the object into the air. This typically happens during thunderstorms when the electrical potential in the atmosphere is particularly high.

Is St. Elmo's Fire dangerous?

St. Elmo's Fire itself is not dangerous and does not pose a direct threat to safety. However, it indicates that the electric field in the atmosphere is strong, which could precede lightning strikes. Therefore, while St. Elmo's Fire is not harmful, it should be considered a warning to seek shelter due to the potential for severe weather.

Can St. Elmo's Fire be seen on airplanes?

Yes, St. Elmo's Fire can be observed on airplanes. Pilots have reported seeing the phenomenon on the windshields and wingtips of aircraft during flights near thunderstorms. The metal body of the airplane acts as a conductor, and the high velocity and altitude can enhance the electric field required to produce St. Elmo's Fire.

What color is St. Elmo's Fire?

St. Elmo's Fire typically appears as a blue or violet glow, emanating from pointed objects. The color can vary slightly depending on the gas composition of the surrounding atmosphere and the specific ionization conditions. The blue hue is due to the spectral emission lines of nitrogen and oxygen, the primary components of Earth's atmosphere.

Has St. Elmo's Fire been reported in places other than at sea?

While St. Elmo's Fire is most famously associated with maritime tales, it has been reported in various terrestrial locations as well. It can occur on tall structures such as church spires, aircraft, and even on the tips of cattle horns. Any pointed object with sufficient electric potential can potentially display St. Elmo's Fire.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments

BabaB

I've always wanted to see the Northern Lights, and now I'd like to see St. Elmo's Fire, also.

My grandfather left home when he was 16 to be a sailor in the North Sea. He never mentioned it, but he must have seen St. Elmo's Fire a number of times. Can you imagine what a thrill (or a scare) it would have been for a teenager to see such a sight out in the middle of the ocean? It's interesting that this phenomena was named after St. Elmo, the patron saint of sailors.

I remember seeing the movie St. Elmo's Fire in the 1980s and I still listen to the soundtrack. The songs make references to the electrical event.

I think that there are a lot of people who don't have any idea what St. Elmo's Fire is, especially kids. It would be a good thing to cover in school.

JessiC

@ddlJohn - My little boy is a Gemini, and I find this to be an incredibly awesome tidbit to regale him with!

I utterly love discoveries such as this that will draw his interest and get him involved in using that beautiful, as of yet uninhibited imagination.

I had never heard the story of St. Elmo’s fire – or of Pollux and Castor – until now. Likewise, I’ve certainly never witnessed the blue light during a storm.

Now, however, I’ve got a new little ditty to entertain and capture my little one with! Thank you!

blackDagger

Oh, this is so cool. Don’t you just love these sorts of things that have long been held a part of mythology and superstition, and then we discover the answers behind them?

I personally absolutely believe in the paranormal and that many superstitions certainly hold some truth to them.

Now, that does not mean that I think that the two Gemini twins are out there causing St. Elmo’s fire, but that science is slowly explaining paranormal events as we learn more and more about the workings of the universe.

In other words, paranormal – to me – is just a word that gives us a definition to hang on events and things that are as of yet indefinable otherwise. That doesn’t mean, however, that they will not one day be explained in full.

dimpley

How enlightening! I’ve heard of St. Elmo’s fire, but never actually new what it was. I’ve certainly never laid eyes on it before!

And, now I am absolutely determined to do so. I am terrified of lightning storms and the like, but this just sounds so incredibly interesting.

Where are the best places to find it and are there are any particular weather conditions other than a lightning storm to look for in order to up your odds of catching the phenomenon in action?

I cannot wait to have a chance to check this out! This is probably the first time in my life I’m looking forward to a storm rather than being petrified of it!

geekish

@bluespirit - From what I can tell there is no special local, rather as the article described you have to be around things such as lightning rods and masts of ships during a storm.

I was curious about this because I had learned about many saints growing up around the Catholic Church but I had never heard of St. Elmo. But now I realize that because I never had been on ship that was likely my cause of never having learned about him.

Fun fact: I thought St. Elmo must have been a sailor. Actually it is thought that his connection to lightning that made him the patron saint of soldiers and why this phenomenon may have been named after him.

bluespirit

I thought St. Elmo's Fire just had to do with the movie and the brat pack! I had never seen the movie as it was a little out of my time period, but had heard of it and the brat pack when I had seen interviews of Charllie Sheen or Rob Lowe (who were in the movie and in the brat pack).

While they are handsome and good actors, I think this description of St. Elmo's Fire is much more exciting than the movie!

Where are you most likely to see St. Elmo's Fire or is there a most likely place?

ddljohn

@fify-- Yes, I've heard several myths and legends about St. Elmo's Fire as well. Some sailors and fisherman also considered St. Elmo's Fire to be God's helping hand.

I believe the Greeks thought that St. Elmo's Fire were the Roman mythological twins called Pollux and Castor. The twins were known to help sailors and other shipwrecked people on the sea. These twins are also associated with the astrological sign Gemini.

The one thing that all of these legends have in common is that there is some sort of divine, out of this world intervention. But people who are not familiar with the seas don't really know about St. Elmo's Fire unless they witnessed it on land.

There is also an old song and film from the 80s called St. Elmo's Fire. Most people are probably more familiar with those.

fify

@turkay1-- No, St. Elmo's Fire doesn't pose any danger for the people or objects around it. Most people are scared of it because they know it involves electricity, but really the amount of electric discharge is nowhere near enough to cause harm.

What I find even more interesting than the actual St. Elmo's Fire phenomenon are the stories and various interpretations of it among common folk.

They say that since St. Elmo's fire appears as a thunderstorm is dying down, sailors have believed that it is the helping hand of St. Elmos protecting them against the storm.

When I was in Asia, I heard interpretations that were exactly the opposite. The fisherman there believed that St. Elmos Fire was a bad omen and probably the presence of a spirit that wanted to harm them. Some even believed that it was the soul of a person who had been killed and was looking for revenge!

It's amazing how when people don't know the science behind an event, they find the most peculiar explanations for it. I wonder what other stories are out there about St. Elmo's Fire.

candyquilt

This is very interesting! I had never heard of this before.

I understand that St. Elmo's fire has nothing to do with actual fire but can it be dangerous otherwise if someone stands inside the "fire" for a while?

Or does it cause damage to electrical objects?

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