As volatile as the weather is on Earth, weather on the Sun can be just as extraordinary. Recently, scientists observed massive magnetic vortices on the surface of the sun, which can lead to a type of solar tornado. The structures were observed by NASA's Solar Dynamics Observatory (SDO), and studied by Xing Li of Aberystwyth University in Wales.
Beyond their shape, solar tornadoes share very few similarities with the tornadoes that terrorize much of the central United States. These tornado-like occurrences, also known as solar prominences, are dense solar structures that extend from the surface of the sun. The exact cause of this phenomenon is still unclear.
"One similarity between them is that material is sucked up from the ground," Li wrote in an email to The News-Letter. "Of course, the sun does not have a ground but atmosphere at lower height is much denser."
Solar tornadoes are shaped by the powerful magnetic field of the sun. These magnetic fields are dynamic and can produce offshoots. The tornadoes usually occur with coronal mass ejections, which is a process during which plasma, a form of superheated ionized gas, is ejected from the sun. They are subsequently taken up by the magnetic field as a swirl of gasses.
"Once some threshold is reached, the surrounding solar corona will experience an even larger explosion: coronal mass ejection," Li wrote. "Huge amounts of charged particles as fast as one thousand kilometers per second are thrown away from the sun into interplanetary space. When such coronal mass ejections are heading toward the Earth, they can impact our space environment, damage satellites, [and] even knock out [the] power grid."
In extreme cases, when the coronal mass ejections strike Earth, they can also cause temporary disruptions in GPS signals and radio communications, due to fluctuations in the electromagnetic field. Moreover, they are also responsible for the stunning neon-colored aurora borealis and aurora australis, or northern and southern lights respectively, seen around Earth's poles. As they come into Earth's atmosphere, they interact with air and release energy, seen as colorful light.
These coronal mass ejections are not to be taken lightly. In the event of a massive eruption, millions of people could lose power during the cold, dark winter and freeze to death.
Astronauts on satellites would be exposed to dangerous levels of radiation, communications on the affected hemisphere could come to a standstill and countless pieces of scientific equipment, including life support systems, would become defunct.
Luckily, the Earth's magnetic field will probably protect us from all but the strongest coronal mass ejections.
By comparison, tornadoes on Earth are caused by the combination of unstable air (warm, humid conditions) and shifting wind directions at different elevations. This leads to shear stress in the air, which when the axis of rotation is shifted, can form a tornado. Tornado wind speeds can get up to 300 mph for an F5 tornado.
The SDO mission was launched in February 2010 aboard an Atlas V rocket from Cape Canaveral, the home of the since retired Space Shuttle program. It was built at NASA's Goddard Spaceflight Center in Greenbelt, Maryland, and carries three instrumentation packages.
The Helioseismic and Magnetic Imager records the magnetic field of then sun. The Atmosphere Imaging Assembly images the sun over a range of wavelengths at short intervals. Lastly, the Extreme Ultraviolet Variability Experiment measures the sun's emission of extreme ultraviolet waves.
Recently, NASA's Solar Dynamics Observatory filmed, for the first time, a massive solar tornado that is bigger than five times the size of Earth. The solar tornado recently witnessed spun at 186,000 mph. Gasses with temperatures up to 3.6 million degrees Fahrenheit were detected to rise from the prominence. It then traveled at rapid speed in a spiral path toward the upper solar atmosphere.
