Gravity Podcast: Solar Storms, with Alex Young

You can listen to the full podcast right here, or read the shortened transcript below.

Dr. Alex Young of NASA's Goddard Space Flight Center. Image credit: NASA.

Jim Green:What do we mean when we use the term "space weather"?

Alex Young:Well, the space weather is that environment of the solar system created by the Sun and the energy and matter that it releases, and the way it interacts with all the bodies of the solar system. [There is] This kind of fairly regular wind that emerges from the Sun, we call it the solar wind, and it is the warm atmosphere of the Sun that gushes into space. It takes the magnetic field of the Sun and sometimes we even get these explosions, and they are huge – almost like tsunamis – that ride the solar wind, and these are the most energetic phenomena that make space weather.

Jim Green:So these are things like flares and coronal mass ejections?

Alex Young:Right. The Sun has a very strong magnetic field and this magnetic field is twisted inside, just as the elastics are twisted; they have tension, they have pressure, [and] sometimes they are writhing enough and they break violently, releasing energy [in the form of] a flash of light that we call a solar flare. And sometimes they spit these big spots of matter. These are called coronal mass ejections (CME), and both [flares and coronal mass ejections] can create shock waves that excite particles [high] speeds and so we have this storm of energetic particles.

Jim Green:These particles can affect the instruments of our spaceship and also have implications for human exploration, not only on [International Space] Station but for when we exceed the low Earth orbit.

Alex Young:Exactly, and they create this very, very dynamic, but dangerous and hostile environment [not only] for humans in space but [also for] all of our technology, because it's all electromagnetic and interacts with technology, which is electrical in nature.

Jim Green: Alex, what is the worst solar flare you've ever seen in the missions you've been to?

Alex Young:Well, the biggest one I know – and it's actually the biggest ever recorded in the space age – was for a period of about two weeks. [During a period between] end of October to beginning of November 2003 [there were the] The Halloween storms, and one of those flares that occurred just at the time of the rotation of the flared region on November 4, created what we call a class X rocket, and this one was off-side. It was bigger than anything we had ever seen, and in fact, our instruments could not even record it, so we had to evaluate its actual size.

Jim Green:When these flares take off and start accelerating the particles, does this happen in all directions or is it very directional?

Alex Young:Torch light is not directional, it's pretty isotropic. So, if you see it anywhere, this region is visible on the sun. But the particles are very directional. They are created by jets and these particles actually enter the sun, creating the light, [and] then streaming in the space.

On July 22, 2012, the Sun released one of the fastest and largest CMEs ever recorded (the giant cloud to the right of this image). A coronagraph blocks the sun's glare. Image credit: ESA & NASA / SOHO.

Jim Green:What is the worst CME you have ever seen?

Alex Young:Well, the worst CME I've ever seen happens to be the biggest we've seen in the space age. In July 2012, an event occurred on the sun side. He was caught by one of our spaceships, STEREO, which [is actually two spacecraft] orbiting the Sun, and we measured this CME in motion at a phenomenal rate of 3,500 kilometers per second. It's the largest, the fastest we've ever recorded.

Jim Green:So these are magnetic field bubbles reconnected and in these bubbles, there is all the atmosphere that the bubbles capture, and they come off and fly awayours?

Alex Young:Exactly. And what's crazy is that they're really huge – they're bigger than the Earth and they get bigger quickly as they move away from the Sun, and very quickly they can fill up large parts of the Inner Solar System. And they carry billions of tons of matter as well as the Sun's magnetic field inside them.

Jim Green:Now, a CME may or may not hit the Earth, but when they do, we will have a beautiful display of auroral lights.

Alex Young:And it's amazing. But there are so many other things that happen when all of these things interact with the Earth's magnetic field and the teardrop bubble around the Earth that we call the magnetosphere.

A magnetically intense active region on the sun. These areas are the starting points for solar flares and coronal mass ejections. Image credit: NASA / SDO.

Jim Green:Have we seen all that the sun can do in terms of space weather?

Alex Young:Certainly not. We did not even see a wink of life from the sun. When the sun was younger, he was a lot more active and we really saw a little [of that]. We know, looking at the historical records of Aurora that there is [have been] huge storms. But we also see signatures in the radioactive elements – carbon 12, beryllium 10. These are left behind by nuclear reactions in the atmosphere with particles [from the Sun] and we can see these traces in things like ice cores and tree rings, so we know that there have been much more important events in the past.

Jim Green:What are some of the great historical solar storms we have studied?

Alex Young:There have been a few in the modern era. There's one I've talked about, the Halloween storms, [which were a] whole series [of events] in October / November 2003. A very famous one, in March 1989, caused a power outage in Quebec in Canada. But the big thing that most people refer to is the so-called Carrington event. This was seen by Richard Carrington in England in September 1859. There was a series of events and he saw the first flare of white light, [which is] a solar flare visible in white light with a telescope, then a few days later, they observed auroras on Earth. This is the first time they make the connection between these magnetic eruptions on the Sun, the flare and something happening here on Earth.

Jim Green:Carrington saw the flare and then a coronal mass ejection took off. Seventeen hours later, there was dawn. Now, coronal mass ejections usually take 80 hours to get here from the sun, and this thing was really moving. There was a huge amount of mass and auroras were observed cutting off the United States, Mexico, and Central America. So, a pretty spectacular event.

Alex Young:It was a really cool event for a lot of reasons and we saw similar things. Even with the July 2012 event, the speed at which were comparable– about 17 hours to reach the distance from the Sun to the Earth.

Jim Green:Now that we have not hit the Earth.

Alex Young:He did not touch the Earth, he hit a spaceship on the side of the Earth, STEREO. But this spaceship was about the same distance.

A close up of a coronal mass ejection. Image credit: NASA / SDO.

Jim Green:Now they [CMEs] come from very big sunspots.

Alex Young:We are talking about sunspots the size of the Earth. And the more these sunspots are big, the more complex they are. We can see the amount of energy that they contain, which gives an indication of the type of activity that we can see.

Jim Green:Are there other events like the Carrington Event in the past?

Alex Young:We talked about it recently, called the Charlemagne Event because it is estimated that it is in a period of about 774 or 775AD, somewhere during the Charle period.magne, and it has been recorded in Carbon 14 in tree rings. This event was 10 to 20 times larger than the Carrington event. And it's just huge.

Jim Green:What would happen to our technological infrastructure if such an event occurred today?

Alex Young:It could be catastrophic. There have been studies by national academies thatestimatethere would certainly be billions of dollars in damage, there are even estimates of up to billions of dollars, because that would have a global impact on our technological infrastructure. We could see power outages around the world and in interconnected power grids in particular. There would also be an impact on communications and we could lose a lot of satellites. We are now in the age of technology that we had not had in 2003, and certainly not in 1989. So we do not really know what a massive or powerful solar event would do to the current infrastructure.

Jim Green:Now that we are more aware of the Sun's activity, how can we protect our technology on Earth?

Alex Young:There are many things we can do. We are simply prediction; that is, trying to make a sort of estimate of when an event is going to occur. Now, as you mentioned, CMEs take a while to get here. But for Solar eruptionyou can not do much. Once you see it, it's here. [In that case] just get ready and have a quick reaction time. Another thing we can do, when we talk about the impact on power grids, is that we can improve the power grids themselves, improve the infrastructure, and even when we know that an event is happening, we can do simple things, like turning the power is off for a short time. It's as if you knew a thunderstorm was brewing at home, the first thing to do is unplug your stereo.

Sunspots visible on the sun disk in white light. Sunspots form in the active regions and their magnetic fields are at the origin of solar flares and CMEs. Image credit: NASA / SDO.

Jim Green:In fact, the way this affects our power grids is really due to auroras. Auroras have huge currents that are in the ionosphere, so when they pass over, they induce in our electricity grid other currents that are not usually present, and so they can overload the transformers and burn them. power outages.

Alex Young:Exactly, because these currents are looking for great drivers to cross.

Jim Green:Do you think there is a link between the space weather and itsimportance to the formation of life in our solar system?

Alex Young:Absolutely! One of the things we know is that the sun has changed over time. He was a lot darker in the past, was running much faster, but he was also a lot more active. We believe that the first Sun produced many Carrington events on a daily basis. The spectrum of this Sun was also different. [Back then] There was a lot more ultraviolet radiation, a lot more x-rays, so all the planets were bathed in huge amounts of radiation. This had an impact on the way the atmospheres themselves were formed. This radiation interacts with these atmospheres, changing their evolution, and it could have an impact on the source of energy needed to trigger life.

Jim Green:One of the things I love to do when I talk to my colleagues is to try to understand how they came into this field. What events in their lives really excited them about their science, gave them that gravitational assistance that propelled them upward to become the scientist that they are today? So, Alex, what's your gravity?

Alex Young:Well, it's a help in several parts. There are some small pushes and then a giant push. When I was young, I saw the original Star Trekin syndication and I was fascinated by this idea of ​​exploring space and especially the character of Mr. Spock, so I thought it would be great to be able to do it. Then, at about the same time, I saw a Carl Sagan show titled Cosmos, [in which he took the viewer] around the universe in a spaceship. I've started to see, hey, I can actually do it. I can actually be an explorer like Mr. Spock, but I can do it in real life and study the Universe from telescopes and spacecraft. It was an exciting time as it was in the early 1980s, so Voyager's results were published. I was writing to NASA and they were sending me photos of Jupiter and Saturn. At the same time that I received specifications for the Space Shuttle, they were just starting to launch it, so it was all happening as I was slowly passing through high school. And my dad was an art teacher and one of his colleagues was a physics professor, so they entered into a deal. The physics teacher's daughter wanted to study art. And I wanted to study physics. So they said, if we could exchange and in the afternoon they go and meet and learn. So I went to meet the physicist while his daughter was studying with my father and I learned physics. He helped me, I built a laser and I went to the science fair and I really understood all that. This kind of meeting is finally concluded, and that is the piece that hit me. It was really serious help.