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NASA's 'IRIS' Project Looks to Reveal Sun's Secrets

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NASA Goddard Space Flight Center heliophysicist Alex Young says the IRIS mission is critical to our understanding of space weather.
Rebecca Sheir
NASA Goddard Space Flight Center heliophysicist Alex Young says the IRIS mission is critical to our understanding of space weather.

June 26, 2013 brings an event that could forever change our understanding of something so hot, its temperatures can be 12,000 times more blistering than the hottest lava on Earth.

We're talking about the sun. And NASA Goddard Space Flight Center heliophysicist Alex Young is pretty well versed when it comes to this sizzling celestial body.

"'Helios' comes from Greek for 'the sun,'" he explains. "So how does the sun, which is the center of our solar system, [drive] everything that's happening? The study of all those processes that are happening throughout the solar system is 'heliophysics.'"

As Young will tell you, at the sun's core, temperatures are approximately 27 million degrees Fahrenheit. At its surface, they're far cooler: more like 10,000 degrees. But as you move outward from the surface, toward what's known as the sun's "corona" ("It's what you see during a total solar eclipse; there's a sort of wispy structure," Young says), temperatures shoot up again, to a sweltering 3.6 million degrees.

"If you're on the Earth and you go higher and higher, the atmosphere gets thinner and colder," Young explains. "But one of the weirdest things about the sun's atmosphere: if you go from the visible surface and move upwards, all of a sudden the temperature just skyrockets."

So that raises two big questions, says Young. One: why is it hotter? And two: how is it hotter?

To find out, NASA is gearing up for a brand new mission it's calling IRIS, short for "Interface Region Imaging Spectrograph."

The 403-pound satellite will launch on June 26, aboard a Pegasus X-L rocket, which, as Young explains, is "kind of like a glorified cruise missile. You strap it on the bottom of a big plane, you take the plane up in the air, and you drop it off and it launches from there."

Once IRIS starts orbiting the Earth, it'll capture images of a mysterious region between the sun's surface and corona: an area known as the "interface region."

"It's sort of the interface between the visible region that we see and this crazy hot corona," Young says.

Now, NASA does have other spacecraft studying the sun, like the Solar Dynamics Observatory, or SDO, which is showing us the whole sun.

But what sets IRIS apart is its ability to zoom in and capture high-resolution images of specific parts of the sun, like the interface region. And in doing so, it will allow us to improve our understanding of space weather, which Young describes as "all of these really dynamic, explosive phenomena" produced by the sun.

Space weather can consist of solar flares ("basically big flashes of light," Young says) and sunspots.

"That's where magnetic fields are coming up through the surface," Young explains. "And they're kind of like rubber bands, and they get all twisted and eventually they pop and they have to release energy."

Then you have these sudden eruptions known as "coronal mass ejections."

"That's where big bubbles of stuff come off the sun and magnetic field, and those big blobs that come away from the sun are traveling a million miles an hour, maybe more," Young says. "And sometimes they're directed at the earth. When those coronal mass ejections slam into our magnetic field, our magnetosphere, it creates these electrical disturbances. And those electrical disturbances can cause all kinds of havoc on our technology."

That havoc can include satellite interference, power-grid failures and disrupted GPS services, which is why Young says when it comes to space weather, we have to understand why it happens, what its effects will be, "and ultimately, can we predict it."

And the sun's interface region plays a key role in how this energy gets through the solar atmosphere and drives space weather. So, while it's often said there's "nothing new under the sun," with the IRIS mission, NASA is hoping to prove that actually, there's plenty new within it.

[Music: "This Is Why I'm Hot" by MIMS from Music Is My Savior]

Photos: NASA's IRIS


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