Short Wave - Getting Closer To The Sun Than Ever Before

Episode Date: December 9, 2019

An ambitious mission to get a spacecraft close to the sun has revealed a strange region of space filled with rapidly flipping magnetic fields and rogue plasma waves. Science correspondent Nell Greenfieldboyce explains how the Parker Solar Probe may help answer one of the biggest mysteries surrounding the sun. Follow Emily Kwong on Twitter @emilykwong1234. Email the show at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey there, Emily Kwong, Shortwave's reporter. I've got Nell Greenfield-Bois, NPR science correspondent here. Hello. Hello. You're here to talk about one of the biggest mysteries surrounding the sun. That's right. So one of the weirdest things about the sun is the fact that it's atmosphere.

It's corona. That's the part that we all saw during the total solar eclipse, the sort of ghostly ring around the sun. That's its atmosphere. And it's hotter than the atmosphere. than the sun's surface. Weird, which is weird. I mean, it's sort of like, imagine the sun as being like a campfire, and you've been around a campfire and the campfire is hot. And imagine if you were walking away from the campfire further and further out, and you just got hotter. It just felt like

things were getting hotter instead of getting colder. That's bizarre. It seems to violate the laws of physics, doesn't it? I mean, that's really strange. Yeah. Why does the sun behave this way? Do we know why? We don't know. And in fact, there's a lot we don't know about the sun. It supports life on Earth, and it's very important. You know, it's our nearest star, but the sun has a lot of mystery to it. And that's why NASA wanted to send this kind of unprecedented mission to get up close. It's called the Parker Solar Probe, and its first batch of results are in the current issue of the journal Nature. People are really excited about it because one of its findings is that the sun's solar wind has clues to this mystery of why the sun's atmosphere is hotter than its surface.

intriguing. Okay. And I heard this probe, this robotic spacecraft we've sent to study the sun, was named after a guy named Eugene Parker, right? Right. Who is that? So he is a 92-year-old scientist who's kind of a superstar, pardon the pud, in the field of studying the sun. And he's made just all kinds of interesting predictions that have turned out to be right and, you know, open a textbook and you can read about the Parker spiral and the Parker equation and the Parker instability and the Parker limit. Now he has the Parker Solar Probe. That's right. Amazing. Well, okay, today on the show, we're going to talk about this probe and its historic mission to get closer to the Sun than we've ever been before. Okay, Nell, we're talking about the Parker Solar Probe

and its mission to the Sun. Where should we start? Well, why don't we start with Eugene Parker? He's the only person to ever have a NASA mission named after him while he's alive. It's kind of a big deal. He's 92 years old. He's retired. And back in the 1950s, he came up with an idea that some people just ridiculed. And his idea was that the space around the sun wasn't just empty, that the sun was actually spewing out this stream of charged particles, constantly spewing these things out. And he called it the solar wind. What a name. It's a cool name. Solar wind. Okay. And so, you know, this was not immediately accepted. You know, it had not, it was just, he was predicting that this should exist. And when I talked with him last year before the probe was launched,

he was surprisingly philosophical about the opposition he faced. Well, it's normal in the scientific world. If you say something new and different, that it will not be believed. So it was no surprise. And it was annoying, but no surprise. He sounds like he kind of expected that at the time. Scientists are pretty skeptical, folks. Still, I think it sort of rankled him a little bit. It must have. I mean, he told me that one person told him that before writing about the sun, he should go to the library and, like, read up on it. And the question is, well, what do they think now? Well, they're all dead by now, so it doesn't really matter. Amazing. The vindication about living your peers. Parker was right about the solar wind. Yeah, he was right about that. Oh, that's cool. Yeah, you can have.

actually hear the wind. That is what NASA says it is. It is data collected by the Voyager 1 probe, which took off in the 1970s. And it's important to the mission of the Parker Solar Probe, this solar wind. So let's talk about the probe. You got to see it in person, right? Which is super cool. What did it look like? So it's pretty big. I mean, you know, we saw it in a big clean room and it sort of towers over you. It looked to me like it was a couple stories high. It sort of looked like a big flashlight. The part that points towards the sun has this kind of mass. It's a massive heat shield. It's a four and a half inch thick layer of foam. And it's sort of, the guy who was working there told me it was sort of like, you know, florist foam, those sort of

like hunks of green foam that you would like stick flowers in to position them. Okay. It's sort of like that, only it's made totally of carbon. Wow. And it has to protect the probe from temperatures as high as 2,500 degrees Fahrenheit. So sort of behind the heat shield, it's room temperature so the instruments can work. But in front of the probe, it's going to get extremely hot. And how? And How fast is this spacecraft going? It goes fast. In fact, at its fastest point, it's going to be going super fast. 430,000 miles per hour. That's like the fastest thing we've ever made by far.

You know, it's about 125 miles per second. So imagine getting from Philadelphia to Washington, D.C. in a second. I want that commute when I go visit my parents. Anyway, this is amazing. This probe, so it launched in 2018, and it's now, orbiting the sun as we speak? That's right. Yeah. And Eugene Parker, the guy who was named after, he got to see it take off. So that was kind of cool to have the namesake of the mission there watching it blast off.

And so far, it's swung close by the sun three times. It kind of makes these flybys of Venus that adjust its orbit. And then over time, it gradually flies by closer and closer to the sun. Okay. So we already have some results from this super speedy Parker Solar probe. and what do those results say? Well, one researcher told me that the data at first was so strange, they thought some of their instruments might be broken. Oh, what did the data say?

Well, remember the solar winds, that sort of stream of charged particles that's constantly coming out of the sun? Yeah. When they get here to Earth, that stream is sort of spread out, and it's not what you see when you get close, like the Parker Solar Probe is.

The Parker Solar Probe is finding all this weird stuff that they'd never expected to see. We'd see suddenly a spike in flow where in just a couple seconds the solar wind would start flowing 300,000 miles an hour faster. That's Justin Casper. He's an astrophysicist at the University of Michigan and one of the Parker Mission investigators. And he told me these spikes would only last for a few seconds to minutes. But they nearly double the speed of the solar wind. And they're so violent, they actually flip the direction of the magnetic field in the solar wind around. That's amazing. Okay.

Here's how Nikki Fox described it to me. She's previously the project scientist for the Parker Solar Probe, and she's now director of NASA's Heliophysics Division. It's kind of like twisting a sort of a rubber hose. It wants to continually straighten itself again. And so whatever is causing these features, as it is straightening out, it's giving out energy. She told me that all this weird stuff they're seeing could be an explanation for what's depositing massive amounts of energy into the atmosphere, heating it up. So this flipping back and forth of the magnetic field, is that what makes the corona so hot? That could be part of it. And, you know, that could

help explain that longstanding mystery of why the sun's atmosphere is so much hotter than its surface. You know, aside from being inherently cool science, what is the value of researching the sun for us on Earth? Well, I mean, the sun supports life on Earth, right? So it's important. It's also, if you want to understand stars, this is like our best shot. Like right now we can't send a space probe to some other star far away. We don't have the technology to do that. And then scientists want to understand what's happening with the solar wind because they want to understand what's called space weather. So it's just this idea that stuff that's happening with the sun actually affects Earth. And you can get disruptions in these, you know, particles coming towards the Earth that can actually cause

damage. I mean, they can disrupt satellites and they can, you know, Even endanger astronauts who are in long-duration space missions. So scientists want to understand what's going on with this stuff so they can better predict these kind of like, you know, unusual events. Super useful information. And what's next for the probe's mission? So it's going to make another approach to the sun in January. But the real closest approach, the one that will be the sort of coolest, is in 2025. And then it's going to come within four million miles of the sun.

Yeah. So what does Eugene Parker think about all of this? Well, I asked Nikki Fox that. And she said that she had actually been to see him earlier this year. And she sort of, you know, got to share all of this cool stuff with him. I showed him a lot of the early science data. And he was very excited and very moved. And he continues to be excited and engaged in the mission. That's beautiful that he lived to see this moment. Now, Greenfield Boys, thank you for swinging by. to tell us about the Barker Solar probe

and this legendary guy, Eugene Parker. Thanks, Emily. I'm Emily Kwong, podcast reporter. This episode was produced by Britt Hansen and edited by Piet Le. We'll be back tomorrow with more shortwave from NPR.