"Sometimes these spikes, or stronger waves, last for a couple seconds, sometimes they last for hundreds of seconds," Kasper says. "We'd see suddenly a spike in flow, where in just a couple seconds the solar wind would start flowing 300,000 miles an hour faster," he says. It turns out that close to the sun, the wind seems to get sped up by powerful, rogue waves that move through the magnetic field, says Kasper. The Parker Solar Probe is designed to plow through the corona with instruments that measure magnetic fields, plasma, and energetic particles.Īll of this lets researchers explore the origin of the solar wind, charged particles that continually spew out of the sun. "The sun is already looking very different from what we've seen before," says Justin Kasper, an astrophysicist at the University of Michigan.įrom Earth, during a total solar eclipse, it's easy to see the sun's corona, an aura of plasma that is the sun's outer atmosphere. So far the probe has swung close to the sun three times, flying around 15 million miles from its surface. In 2025, it will come within 4 million miles of the sun's surface, or about one-tenth the orbital distance of Mercury, according to NASA. Flybys of Venus help it adjust its orbit to gradually get closer to the sun, hurtling around the star at 430,000 miles per hour. The Parker Solar Probe was built to withstand searing temperatures of up to 2,500 degrees Fahrenheit. But the sun also has dangers associated with it," says David McComas, an astrophysicist at the Princeton Plasma Physics Laboratory. "The sun, of course, is the source of life on Earth and the reason we can all be here. They also could help scientists better understand and predict solar storms that might disrupt vital artificial satellites that orbit our planet. Scientists say the findings, described in a series of reports in the journal Nature, could help explain long-standing mysteries - like why the sun's extended atmosphere is hotter than its surface. These surprises are among just some of the first observations by NASA's Parker Solar Probe, which blasted off last year to get up-close-and-personal with our nearest star. Coronal loops are probably one of the keys in this ongoing investigation.KTSDesign/Science Photo Library/Getty ImagesĪn unprecedented mission to venture close to the sun has revealed a strange region of space filled with rapidly flipping magnetic fields and rogue plasma waves. Scientists suspect that energy trapped in magnetic fields somehow causes this intense heating. One mystery of the Sun that scientists are actively trying to solve is why the Sun's atmosphere is much hotter than the Sun's surface. They are most easily seen in images taken in the extreme ultraviolet and X-ray portions of the electromagnetic spectrum. Some loops are extremely hot, having temperatures well above a million degrees.Ĭoronal loops are more common around solar max, the time in the sunspot cycle when the Sun's magnetic field is highly disturbed and sunspots are numerous. The larger loops extend upwards many thousands of kilometers above the photosphere into the solar corona, the Sun's upper atmosphere. Coronal loops are often "rooted" in sunspots, arcing between pairs of sunspots with opposite magnetic poles.Ĭoronal loops come in many sizes. Sunspots are actually the visible manifestations of places on the Sun's surface where powerful magnetic fields "break through" the photosphere (surface) and extend into the Sun's atmosphere. The electrified plasma flows along the curving lines of powerful magnetic fields, giving the coronal loops their characteristic shapes.Ĭoronal loops are often, but not always, associated with sunspots. Coronal loops in the Sun's atmosphere as viewed in ultraviolet "light."Ĭoronal loops are bright, curving structures that appear as arcs above the Sun's surface.
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