The solar orbiter has spotted an odd snake-like filament crawl across the sun’s surface just before a massive plasma eruption. The filament originated in a sunspot, a cooler region on the sun’s surface where the star’s magnetic field is twisted. The “snake” took three hours to slither across the sun’s disk at a speed of 105 miles (170 kilometers) per second, or 378,000 mph (608,000 km/h), according to a statement from the European Space Agency (ESA), which operates the spacecraft. In the time-lapse sequence constructed from images captured by the Solar Orbiter’s Extreme Ultraviolet Imager, the “snake” glides across the disk within a second.
The snake is a tube of cool plasma suspended by magnetic fields in the hotter surrounding plasma of the sun’s atmosphere. Plasma is a state of matter in which a gas is so hot that its atoms begin to lose some of their outer particles, called electrons. This loss makes the gas electrically charged and therefore susceptible to magnetic fields. All the gas in the sun’s atmosphere is plasma because the temperature here is more than a million degrees centigrade.
What makes the snake so intriguing is that it began in a solar active region that later erupted, ejecting billions of tons of plasma into space. This raises the possibility that the snake was a sort of precursor to this event—and the Solar Orbiter caught it all on numerous instruments.
More intriguing still is that the plasma from this eruption, known as a coronal mass ejection, happened to sweep over NASA’s Parker Solar Probe, allowing its instruments to measure the contents of the eruption.
Being able to see an eruption take place and then sample the ejected gases, either with its instruments or those of another spacecraft, is one of Solar Orbiter’s principal scientific aims. It will allow a better understanding to be developed of solar activity and the way it creates “space weather,” which can disrupt satellites and other technology on Earth.
Solar Orbiter is an international space mission operated by ESA in collaboration with NASA. It launched on February 10, 2020, and earlier this month celebrated its 1000th day in space.