Swirling Spicules
(Photo : NASA’s Goddard Space Flight Center) After a long time, astronomers finally have an idea where this spicules come from.

The occurrence of the jets of solar plasma has continued to bother astronomers until to this day. Luckily, some clues suggest there are magnetic clashes that occur on the surface of the sun.

SOLAR MYSTERY

In an interview with Space.com, Alphonse Sterling, solar astrophysicist at NASA's Marshall Space Flight Center and co-author of the study, explained, "we have seen them for about 140 years, but we don't know what drives them." The spicules were discovered far back in 1877. Still, generations of astronomers were never able to figure out its origins because of their brief appearances--spicules often last for 12 minutes or less with the solar plasma moving between 33,550 to 89.475 miles per hour and there are occasions when the plasma can be dispersed faster at 223,690 miles per hour.

To finally solve this mystery, the astronomers behind the study used the Goode Solar Telescope located at the Big Bear Solar Observatory in California. Wenda Cao, director of the Big Bear Solar Observatory and a solar physicist at the New Jersey Institute of Technology and co-author of this study, explained: "This telescope is the highest-resolution solar telescope ever built in the United States. You need a high-resolution telescope with high sensitivity to see features like spicules, which are very small, narrow features of the sun." 

According to the study, which was published in Science, many spicules emerge within moments of the formation of a patch on the photosphere, usually with a magnetic field reversed from its surroundings. For instance, spicules will appear from a patch that was polarized magnetic north after it erupted from a region with mostly polarized south. These findings suggest that spicules could have been formed because of magnetic reconnection. 

Magnetic reconnection is the phenomenon when two magnetic regions with different orientation in field lines encounter each other. Those magnetic fields will then clash and break. Later on, they will reconnect with each other, converting magnetic energy to heat and kinetic energy.

Prior to this study, there are previous findings that also suggested that magnetic reconnections can also be the reason behind larger outbursts such as coronal jets, solar flares, and coronal mass ejections. Sterling explained that these phenomena could have undergone the same processes as the spicules. Also, other studies suggest that the presence of the spicules might explain why the sun's outermost layer, the corona, is hotter than the layers beneath it. Compared to the corona, the photosphere, which is the sun's visible layer, reaches a temperature of about 5,500 degrees Celsius and the chromosphere is slightly cooler at 4,320 degrees Celsius. The corona, on the other hand, can reach 1 million degrees Celsius to more than 10 million degrees.