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Dr. Michelle Thaller is an astronomer who studies binary stars and the life cycles of stars. She is Assistant Director of Science Communication at NASA. She went to college at[…]
  • 2012  was supposed to be an apocalyptic year according to the Mayans. Although the world never came to an end, in 2012, something else happened that had astrophysicists worried – the earth barely avoided catastrophe as a massive sun storm erupted. 
  • Sun storms happen more often than we think, with protons and electrons traveling past the earth at a speed of one million miles per hour. If these particles and solar storms are responsible for the unliveable climate on Venus and Mars, why has Earth not been impacted yet?
  • Earth is rarely impacted by the sun’s solar storms because of the strong magnetic field that surrounds the planet, protecting us from solar wind. Although this magnetic field does a great job at protecting the earth and everyone on it, all around us experts are monitoring space weather, in the event of a big storm that could head our way. 

MICHELLE THALLER: It was the year 2012. I was having sort of a difficult year that year because people had this idea of the Mayan apocalypse. We kept telling people that there was really no reason to worry about anything. There was nothing unusual astronomically happening. Of course, (laughs) what almost happened would have been really bad for me to deal with.

The sun was in a naturally active period that year. Every 11 years or so, the sun becomes very active, and then it gets quieter again. But 2012 and 2013 were the peak of this natural cycle. And so what happened actually is that there was a colossal coronal mass ejection. The thing, though, is it went off on the other side of the sun from the earth. And we had satellites out there in that other direction, out in the solar system. And they got knocked silly by this big burst of charged particles from the sun. And so we looked at that, and we were able to observe it and see what had happened and track it and all of that. We all kind of went, "whew." (laughs)

The source of these high-energy particles and exactly how they get accelerated away from the sun is what we're studying right now. When I say high-energy particles, I'm talking electrons and protons and sometimes as large as the nucleus of a helium atom, something like that. And they get blasted through our solar system at a million miles an hour in some cases. And so we have this very high-energy wind. It changes planets. It's responsible for Mars losing its atmosphere over time and becoming this cold, dead desert. It's responsible for Venus becoming this hellish thing that we know it. It actually blasted away all of the lighter molecules, like water, and it left

Venus with an atmosphere of carbon dioxide and sulfuric acid and, ugh, yeah, really bad stuff.

The only reason the earth is not really affected by it much is because we have a very strong magnetic field. And so our molten metal core, all that molten metal moving around inside the earth generates a magnetic bottle around the earth. And that protects us from the solar wind.

But someday, the sun will actually pretty much blast away our atmosphere. So planets change.

We have this early warning system to see if there's something dangerous coming from the sun. And we would have probably about a day's notice as one of these big storms made its way through the sun. The sun we think of as putting off lots of light, and light travels at the speed of light, which takes about eight minutes to get from the sun to us. But this isn't light. These are charged particles, protons and electrons. And although they may be moving millions of miles an hour, it still will take them about a day or more to get to the earth. So we will have some warning.

The solar wind normally doesn't really have much danger to us or the environment in space. But just like weather implies, when you're dealing with space weather, sometimes there's a really big line of thunderstorms coming through. So in the case of the sun, the sun sometimes has very, very violent storms. And these are storms caused by the chaotic, twisting magnetic field of the sun. Some of the hot gas oN the surface of the sun actually gets accelerated so quickly by these magnetic fields that it just breaks off and takes off into space. And in one moment, you

could have trillions of tons of fast, high-moving, charged material coming out towards the Earth.

Now, that's not actually very dangerous to us biologically, but what that can do is carry a huge amount of electrical and magnetic energy. All of a sudden, all these charged particles hit the magnetic field of the Earth. And it can actually dump electric current right into our magnetic field. In the case of all of our satellites up above the atmosphere, they're very at risk. So we can basically shut them down, put them to sleep for a little while. And of course, that energy burst will hit them, and it may damage their detectors, but at least most of the electronics are shut down at the time, and we can recover them, hopefully.

And then there may even be plans that are necessary to shut down parts of power grids because I think the biggest danger of these things to us is that when they actually hit the Earth's field, you can have so much, again, energy in that magnetic field of the earth that it could fry our power grids. Think about how bad it would be if all the power on eart just went out because of

one of these solar storms. That could conceivably cause billions or maybe even trillions of dollars of damage. So there are people rehearsing these scenarios. There are people trying to figure out how we would shut things down, how we would protect ourselves. And then we have our fleet of satellites trying to observe the sun all the time.

But yes, all around you, there are people monitoring space weather and getting ready for a big storm.

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