What do solar flares do to satellites?

How are solar flares formed, and how can they disrupt our satellites?
31 January 2023

Interview with 

Rosemary Williams, University of Edinburgh


A solar flare.


The space above our planet might seem cold and empty, but there’s a million mile an hour maelstrom whipping past the planet all the time. It’s called the solar wind and it’s a flurry of charged, high-energy particles ejected constantly from the Sun. Most of these are batted harmlessly away by the planet’s magnetic field, shielding us and our 8000 satellites. But sometimes the Sun erupts something far more forceful and far more dangerous, and which can wipe out a satellite in seconds. Here to explain this threat, and what we can do about it, former NASA intern and guide at the Griffith Observatory in California, Rosemary Williams.

Rosemary - A solar flare happens when the magnetic field lines of the sun, they get all twisted up. The magnetic field lines of the sun are already very, very chaotic and sometimes they can get twisted up. And when that happens, large bursts of energy are ejected from the sun. If we are in the path of that large burst of energy, called a solar flare, it can impact things like satellites, auroras on earth might be stronger, and in very, very extreme cases, it can take down satellites, their communications. It can impact radio GPS on earth. So, you know, ranging from very, very small solar flares that happen on a daily basis to the larger ones like the Carrington event that happened in the late 1850s that if it happened today would be very devastating. But that's kind of the big one that we think of.

Chris - Are these solar flares effectively the solar wind on steroids, or are they a different effect?

Rosemary - I think that they are a bit different. The solar wind just happens as charged particles. These ions from the sun are just kind of getting blown away. But the solar flares happen when you have this twisting of the magnetic field that causes the ejection. Sometimes matter, that's when it's called a coronal mass ejection, but sometimes just radiation or light, which is a solar flare.

Chris - Why is that deleterious for our satellites?

Rosemary - A few things. The first, when you have particles that are moving that have a charge, it creates an electric field. And so when you have these particles moving past the sensitive electronics on your satellites, it can mess up those electronics. It can cause communications to go down just because they are quite small. And so being overloaded with all of that energy can be very detrimental. The second thing is that these charged particles are bombarding our atmosphere and they actually ionize this upper part of our atmosphere called the ionosphere. It absorbs all of this energy. And when you have a very intense solar storm, a lot of those particles are ionized. And what that does is it kind of thickens up the atmosphere that the satellites are traveling in. Satellites are gonna be interacting with particles on a daily basis, but not very many. But when you have these huge solar storms, it makes that ionosphere thicker, which causes drag of your satellites and can actually cause them to deteriorate in orbit and crash back down to earth, which you also really don't want.

Chris - Of course. What can we do about this then? Is there anything that can physically be done either to detect it's going to happen and give us some forewarning or stop the consequences?

Rosemary - So there's a few things that you can do, both for satellites and astronauts that are in space and for the people who are down on earth. So for satellites, what they do to protect from solar flares, especially if they know that they're gonna be up there active, sending back data during a period of high solar activity, is they are going to work to shield those sensitive electronics with aluminum just to protect those aspects. And the second thing is, if there are astronauts that are at risk for getting hit by a solar flare while they're up in the ISS or if we are going on the Artemis mission that's going back to the moon, those astronauts are not going to be protected by the Earth's magnetic field. So they're going to want to reinforce those ships, make sure that there's good radiation protection. NASA and ESA are constantly surveying the sun, looking for solar storm solar flares, and you can kind of predict when those are gonna happen by looking for sunspots, which are these darker areas on the sun, and they signify a lot of activity surrounding the magnetic fields. And when you have a lot of activity with the magnetic fields, you are going to get solar flares, coronal mass ejections, all of that.

Chris - How much warning might we get when, when we're doing this sort of space weather forecasting where you were saying that astronomers are keeping an eye on what the sun's up to for danger or warning signs, how much lead time when we see those signs before one of these things could be coming our way?

Rosemary - I'm not sure on the exact amount of time. I know that it takes light about eight minutes to get from the sun to earth, but I assume that scientists that are sitting the sun are gonna be able to predict maybe like a couple days in advance. But beyond that, I'm not exactly sure.

Chris - Is that enough time to put in place the sorts of mitigations you've been talking about.

Rosemary - So that's not, which is why it's really important for us to be proactive about this kind of thing because solar flares and coronal mass ejections are inevitable. And so we need to prepare for these events.

Chris - It's just that we've exported so much of our life into the heavens now without us even realizing it. I gave the example of the ATM, which are in cahoots with a GPS system, just to get a time code so that they know when they're dispensing your money and they can't work without it, because otherwise people will be ripping off the bank. We've got stock exchanges, trading shares, and they're doing those accurate trades based on time signatures from space. Those are just two financial examples. You can just imagine if this happened and, and we've got the sorts of satellite burden in space that Elon Musk wants to see there, we will inevitably have exported even more of our life heavenwards, it could get really nasty quite quickly if something went wrong, couldn't it?

Rosemary - It could get very nasty. My astronomy professor would always refer back to, you could live without your cell phone potentially for a couple days, maybe even weeks. But the thing that's really gonna hurt society is living without refrigeration. We really rely on being able to have access to fresh food and that in the event of a solar flare coming in and taking out a power grid if it's not prepared, that's the thing that we really need to focus on is making sure that people still have access to fresh food and water. Not even necessarily like the laptop or cell phone aspect of it. Just kind of our basic human needs.


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