NOV 28, 2016

Researchers Recreate Sun's Coronal Loops in the Lab

WRITTEN BY: Anthony Bouchard

Many people who think of the Sun quickly imagine a ball of fire in space, but the Sun isn’t fire at all. It’s a glowing ball of nuclear fusion, and it has its own physical properties that we’re still only beginning to understand.
 
One of those properties has to do with strands of plasma material that appear to eject and loop across the Sun’s surface, known as coronal loops. These look a lot like jump ropes that slither out of the Sun’s surface and move in peculiarly suave motions along the star’s magnetic fields.
 
Now, for the first time, scientists from Caltech have reportedly recreated scale models of these kinds of coronal loops in the lab in which they are bound to a surface made to simulate the Sun. These scale models give scientists a way to study their physical and chemical effects in ways we’ve never been able to before and may spark additional discoveries.
 

 Image Credit: P. Bellan/Caltech

Understanding how these coronal loops work is a big mystery that scientists can’t wait to crack. When they erupt from the Sun’s surface, they can sometimes dematerialize and eject charged particles from the Sun’s surface at speeds of more than 2,000 miles per second. These particles, which then travel through space, can often bombard the Earth, where our magnetic field is known to protect us from it.
 


On the other hand, we know our magnetic field was recently weakened from a very intense solar storm, and so it’s important to better understand how we can protect ourselves in the future such that our planet never becomes like Mars; a barren wasteland with a weak magnetic field.
 
Fortunately, these lab-made coronal loops do offer some insight as to what exactly happens when the loops break apart and particles erupt. The findings are published in the Geophysical Research Letters and can help us better understand the energy behind them.
 
"Studying coronal mass ejections is challenging, since humans do not know how and when the sun will erupt. But laboratory experiments permit the control of eruption parameters and enable the systematic explorations of eruption dynamics," says Bao Ha, the lead author of the paper.
 
"While experiments with the same eruption parameters are easily reproducible, the loop dynamics vary depending on the configuration of the strapping magnetic field."
 
What makes this coronal loop model different from other lab-created models in the past is that the researchers have been able to reproduce the Sun’s unique strapping effect inside of a vacuum chamber. Special electromagnetic coils reportedly made this possible.
 
Although the coronal loops are only about 5 feet long and never travel more than a few centimeters away from the simulated solar surface, the model does allow the researchers to study the critical point in time where the corona breaks apart and unleashes its energy.
 
The next order of business, according to the Caltech blog, is to take careful measurements of the simulated corona to learn more about it. They’ll be measuring things like the magnetic field and the waves of particles that get released whenever the corona breaks apart, just like it does on the Sun in our solar system.
 
Source: Caltech