New Discovery: Elusive Solar Spicules Triggered by Magnetic 'Earthquakes' Creating Shockwaves Across Our Sun
An international team of scientists has pulled back the curtain to reveal what creates mysterious plasma "spicules" on our Sun, according to reports from Phys.Org. Their paper was published in the journal Science.
Solar spicules are supersonic jets of plasma emitted from shockwaves in the Sun's chromosphere. (The chromosphere is the thin red ring of sunlight that we see during a total solar eclipse, with temperatures at a searing 36,000° Fahrenheit.) There are as many as 1,000,000 spicules on the surface of the Sun at any point in time. But spicules only happen for a short amount of time – perhaps a couple of minutes each – which makes them hard to study. We could watch them as they occurred, but we didn't know how they happened or when and where they would peak.
Using the Goode Solar Telescope at Big Bear Solar Observatory two hours outside of Los Angeles, CA, researchers decided to take a closer look. They observed that, shortly before a spicule formed, the area where it appeared on the Sun's surface had an inverted magnetic field compared to the area around it.
Scientists think that a phenomenon called "magnetic reconnection" might be what causes spicules to form. Magnetic reconnection is what happens when magnetic field lines flowing in opposite directions collide, generating a massive amount of heat and kinetic energy. It's similar in concept to tectonic plates breaking free from each other to generate an earthquake – except, this time, the tectonic plates are made of impossibly strong magnetic forces and the earthquake is a supersonic jet of scorching plasma.
A subsequent investigation used data from NASA's Solar Dynamics Observatory. Focusing on data from the same time and location as their observations at Big Bear, scientists revealed the spicule as it erupted, and ions glowing to indicate that the temperature of this spicule was over 1,800,000° F as it transferred this heat into the Sun's corona.
These are all just clues, of course, to a puzzle that will take much longer to unravel. It's a subtle reminder that we still know precious little about our closest star.
Check out this video below from SciTech Daily using footage from the NASA Solar Dynamics Observatory: you can see dozens of spicules all over the surface.