Space

NASA Scientists Discover Space Weather in Action on the Sun (Video)

Catherine Griffin
First Posted: Jul 16, 2013 07:56 AM EDT

NASA scientists have gotten a new look at the mysterious phenomenon behind space weather--magnetic reconnection. They've created a comprehensive movie of the event, revealing a little bit more about how our sun slings solar flares and coronal mass ejections into the depths of space.

Magnetic reconnection occurs when magnetic field lines come together, break apart and then exchange partners, snapping into new positions and releasing a jolt of magnetic energy on the sun. This process lies at the heart of the giant explosions that fling billions of particles and radiation across the solar system, causing space weather. Despite knowing about this type of event, though, researchers still aren't sure how to predict one.

Now, researchers have discovered rare, direct images of magnetic reconnection as it was happening to the sun, taken by NASA's Solar Dynamics Observatory (SDO). The comprehensive set of data could be used to constrain and improve models that study this process that occurs on the sun.

Magnetic field lines are invisible, which means that it's almost impossible to directly observe magnetic reconnection. Yet in these images, the field lines naturally force charged particles, also known as plasma, to course along their length. This material appears as bright lines that loop and arc through the sun's atmosphere. Because the plasma is visible, researchers are able to map the field lines.

"It can often be hard to tell what's truly happening in three dimensions from these images, since the pictures themselves are two-dimensional," said Gordon Holman, one of the researchers, in a news release. "But if you look long enough and compare data from other instruments, you can make a good case for what's going on."

The researchers then turned to a second spacecraft, known as the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Able to collect spectrograms, the spacecraft collected data that showed researchers where exceptionally hot material was present on the sun. By combining the RHESSI data with SDO information, the researchers could confirm previous models and theories.

So what exactly did they find out? Below the surface of the sun, plasma flows. Magnetic loops emerge from this flow and set up areas of positive magnetic poles lying next to negative ones. The loops arc up from one polarity to the other, twisting and growing as the positive and negative poles of the plasma beneath the sun's surface slip past one another. Eventually, the magnetic field lines buckle inward, touch and reconnect while releasing energy.

The findings reveal a little bit more about magnetic field lines which could, in turn, allow researchers to predict space weather. In addition, the new images could allow scientists to estimate how much material goes into the process and how much comes out.

The findings are published in the journal Nature Physics.

Want to see the new images for yourself? Check out the video below, courtesy of NASA and YouTube.

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