For instance, the number of observed sunspots has been much higher than predicted. In April 2019, the Solar Cycle 25 Prediction Panel, which is made up of dozens of scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA), released its forecast for Solar Cycle 25, suggesting that the solar maximum would likely begin sometime in 2025 and would be comparable in size to the maximum of Solar Cycle 24, which peaked unusually late between mid-2014 and early 2016 and was quite weak compared with past solar maximums.īut from the beginning, the forecast seemed off. Sunspots are almost completely absent at solar minimum and increase in numbers until a peak at solar maximum, but there's a lot of variation from cycle to cycle. "By looking at those sunspots we can get an idea of how strong and complex the sun's magnetic field is at that moment."Ī time-lapse image of two major sunspot groups moving across the surface of the sun between Dec. "Sunspots appear when strong magnetic fields poke through the surface of the sun," James said. To determine where we are in the solar cycle, researchers monitor sunspots - darker, cooler, circular patches of our local star's surface where coronal loops form. Related: Could a solar storm ever destroy Earth? This ushers in the end of the cycle and the beginning of a new solar minimum, James said. Sometimes, flares also bring enormous, magnetized clouds of fast-moving particles, known as coronal mass ejections (CMEs).Ī few years after the maximum, the sun's magnetic field "snaps" and then completely flips. These fiery ribbons can then snap as the sun's magnetic field realigns, releasing bright flashes of light and radiation, known as solar flares. As a result, the sun's magnetic field gradually weakens, and solar activity begins to ramp up: Plasma rises from the star's surface and forms massive magnetized horseshoes, known as coronal loops, that pepper the sun's lower atmosphere. (Image credit: NASA/Solar and Heliospheric Observatory)īut the magnetic field slowly gets tangled, with some regions becoming more magnetized than others, James said. A butterfly-shaped coronal mass ejection explodes from the sun's far side on March 10.
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