Could the Carrington Event happen again?

January 24, 2025

Laura Baisas

On a hot and humid Florida night in late August 1859, the sky suddenly lit up. But it was not from fireflies or a fireswamp. Instead, it was the Northern Lights–or aurora borealis. The aurora is usually seen in far more northern latitudes, but it had somehow reached the subtropics and danced across the night sky. Reports of the aurora came in from as far south as Central America and some in the Rocky Mountains even believed it was morning because the sky was so bright.

Across the Atlantic Ocean in England, a wealthy amateur astronomer named Richard Carrington was also watching the cosmos. However, Carringon had his eyes on the Sun and its various sunspots and solar flares.

“Sunspots are there all the time, almost. You can see them with a small telescope,” University of Glasgow astrophysicist Hugh Hudson tells Popular Science. “Carrington was sketching the spots’ areas and recording them. He noticed at a certain point that there were two bright patches of light that appeared in the sunspot group, which ought not to have been there.”

What Carrington and the awestruck people of the subtropical Atlantic saw were related. The aurora was a result of the most intense solar storm in recorded history, now called the Carrington Event. These solar storms can send out large clouds of electrified gas and dust at up to two million miles per hour. If and when these particles reach Earth, it can disrupt and distort Earth’s magnetic field.

The Carrington Event was so large that these particles interacting with Earth’s magnetic field impacted telecommunications.

“There were sparks that were so intense that the wires caught fire, in some places,” says Hudson. “Some of the telegraph operators were shocked and burnt. When you connect the long wires together for power distribution, you’re asking for trouble when surges like that happen.”

Engineers have since learned a great deal about how to handle those large wires since the Carrington Event. However, our reliance on electricity has only grown exponentially. A flare of similar–or even greater like Miyake Events–magnitude still could happen and the effects are of major interest to sci-fi aficionados and scientists alike. With so much more technology at risk than just the telegraph wires of the Nineteenth Century, the effects could be catastrophic.

“In a world that is now so dependent on electricity and electronics, a similar event has the potential to cause widespread disruptions and damage to the electronics aboard Earth-orbiting satellites, ground-based electronics, and the power grid,” Alex Gianninas, an astrophysicist at Connecticut College tells Popular Science.

Our in-space infrastructure, such as, telecommunication satellites are also particularly vulnerable to the Sun’s coronal mass ejections (CME). CMEs are large eruptions at the surface of the Sun that shoot charge particles out into space. All of that energy from the particles can degrade solar panels, damage navigation systems, and alter orbital paths, potentially causing mass collisions and excess space debris.

While there is constant activity happening on the surface of the Sun, there are generally more low intensity flares than higher intensity ones. The sunspot activity that creates these storms and flares also rises and falls on a roughly 11-year cycle. This year, we are heading into the maximum level of this cycle. Larger solar storms are most likely to occur during solar maximum, sometimes with several per day. During solar minima, these can pop up less than one per week.

“Geomagnetic storms, and more specifically, the CMEs that cause them, increase in frequency and intensity as the solar cycle reaches its maximum,” says Gianninas. “We are currently in Solar Cycle 25 and are still heading toward the maximum, which is predicted to occur this coming summer, likely in July.”

While some scientists estimate that the chances of a solar storm like the Carrington Event happening in the next century are at 12 percent or less, it is still a threat to be taken seriously. Currently, an array of satellites are constantly monitoring the Sun. These include the Geostationary Operational Environmental Satellite (GOES), the two Solar TErrestrial RElations Observatory satellites (STEREO-A and -B), the Solar Dynamics Observatory (SDO). These send back data and images in both visible and invisible light, so we can see a wide range of activity. 

According to Gianninas, it can take between several hours and a few days for the particles from a CME to reach Earth, so there is some advance warning that something is coming. NOAA’s Space Weather Prediction Center also tracks all of this activity and can be a good resource for determining where and when the aurora might be visible. This can give utility companies, satellite operators, and crew aboard the International Space Station some time to prepare their systems for impact. For the general public, there is not too much to do beyond charging up devices and making sure you have general emergency supplies like water, batteries, and flashlights..

For scientists and citizen scientists alike, this combination of potential doom and the big questions about our origins are part of what makes studying this solar activity so exciting.

“People are so fascinated by the origin of life and the fundamental questions that the stars inspire in us,” says Hudson. “I think the Sun is in the same category. It’s just something very close by and familiar and yet we have eclipses and strange things happen. So it’s not surprising that 10-year-olds can be amazed by the same thing as adults.”

 

Does the Sun make noise?

December 19, 2024

Harri Weber

The sun is a singular experience in Earthly life. We see it. We feel it. But we can’t seem to hear it.

If we did, would it sound like an explosion? Or a primordial heartbeat? Or just a dull roar, bellowing 93 million miles away? The sun is huge—roughly 100 times wider than Earth, and it’s especially active lately—so much so that its eruptions can distort GPS, degrade communications, and create auroras. So what’s with the silent treatment? These questions and more cascade from a Popular Science reader’s seemingly simple ask: Does the sun make noise?

“The basic answer is no, not for us,” Chris Impey, an astronomer and professor at the University of Arizona, said in a call with Popular Science. “The sun doesn’t make noise because noise, or sound, needs a medium to carry it,” Impey explained. Essentially, the space “between us and the sun is almost a perfect vacuum, so sound can’t travel through that.” Impey added, “So whatever the sun is doing, it’s not transmitting sound to us.”

Bummer! Or… great! Maybe we’re fortunate to not hear the big plasma ball, but with virtually nothing in the way, how come sound doesn’t travel past the emptiness to our ear drums?

“Sound is so funny. It’s a pressure wave,” explained Shauna Edson, an astronomy educator at the National Air and Space Museum in D.C. “It has to move through something, and our ears are adapted to interpret those pressure waves and turn them into a sound that our brain can understand.” To help people visualize how sound works, Edson said she asks them to imagine a row of beach balls.

“If you pushed on the ball at the end of the line, it would roll into the next ball, which would bump into the next ball, and they would all kind of—boom, boom, boom,” she explained. “The push would travel from ball to ball, all the way down the line, as a wave. That is what sound does to the molecules of air or liquid or solid that they’re moving through.” In space, the molecules are “so few and far between,” Edson said, “that even if you pushed on one, there’s nothing else nearby for it to push on, so the wave can’t keep going.” (Hence, the famous Alien tagline, “In space no one can hear you scream.”)

So, the sun can’t make sound as we conceptualize it on Earth because of the vacuum of space. But still, given how big and energetic it is, isn’t the sun doing something that’s at least sound-like?

“The sun has oscillations and vibrations,” offered Impey, “so in a sense, it does have some of the elements of sound within it.” But even so, because the sun is so large relative to Earth, “all the activity in [it] is incredibly low-frequency,” Impey said. In other words, sun activity is definitely not the sort of thing human ears evolved to perceive. Cool—but why, then, are there audio clips online offering otherworldly snippets of oscillations or solar winds via Stanford and Johns Hopkins? This is where something called sonification comes in.

“It’s quite a clever idea in science, where you take—in astronomy particularly—you take some distant phenomenon, like a galaxy; or a black hole, you know, sucking in matter; or the atmospheric motions of Jupiter; or the sun itself, and you turn the signals that are happening in that domain into sound waves, just as a way of realizing them in a way that’s not visual,” Impey said. The technique helps scientists represent data, but according to Impey it also “sort of misrepresents the physics. It’s not a real sound.”

Impey elaborated that sonification is sort of like viewing a vivid infrared image from the James Webb Space Telescope on your phone screen. “They’re not real colors because the radiation that was being detected was not visible to the naked eye.”

Back to sonification: “It’s a way of experiencing a phenomenon that’s not really for the human senses at all,” explained Impey.

There are some good reasons why experts turn to sound to help them interpret such raw data. “Sound is one of the ways that humans make sense of our environment,” said Edson.

“We might hear raindrops or wind blowing, and that tells us about the weather without us needing to look outside. We hear ambulance sirens that tell us we need to get out of the way.” Edson said, “But sound is also a way of learning.” Like a mechanic listens to an engine, or a doctor listens to a heart, for anomalies, scientists convert and condense data into sound to figure out what’s happening. “You can hear years and years of changes in a few seconds or minutes,” Edson explained, and “sometimes there are patterns that will show up in the sound that you wouldn’t have noticed.”

Like Earth, our sun has its own activity cycle. And it’s been quite busy lately. “Right now we’re in what we call solar maximum,” said Edson. “So there’s a ton of sunspots. There are lots of flares. We’ve been seeing auroras in places we don’t usually.”

If you sonify the sunspot data, “when it gets turned into sound, you can hear the up and down of that 11-year cycle,” explained Edson, “and it does kind of sound like a heartbeat.”

(The expert did not say if it went something like ba boom ba boom, or lub dub lub dub.)