The Sun could be entering a new cycle of activity, potentially as soon as this month, a scientist has said.
Our star generates a powerful magnetic field which goes through roughly 11-year-long cycles. At the end of this period, the polarity of this magnetic field flips, meaning that the north and south poles switch.
Scientists refer to end of this cycle as a solar minimum, the period of lowest activity. The middle of the cycle—the solar maximum—on the other hand is a period of high activity. The last solar minimum took place in 2009.
Clinton Wallace, director of the National Oceanographic and Atmospheric Administration’s Space Weather Prediction Center, predicts that the transition to a new solar cycle—solar cycle 25—could take place this month, although it is difficult to determine exactly when they occur.
Solar cycles have been tracked since 1755, however, the start of any cycle can only be determined at least six months after the minimum takes place.
“In the next year we’ll know when we’ve hit minimum,” Wallace said during a presentation at the National Academies of Sciences on April 1, Space.com reported.
During solar maximums, sunspots increase in frequency on our star. These are temporary dark patches which appear in the Sun’s photosphere, or outer shell.
As the solar cycle proceeds, other solar phenomena, such as solar flares and coronal mass ejections, also increase, according to NASA. These phenomena emit vast amounts of energy that can even have an impact on the Earth. For example, solar flares can sometimes disrupt communication systems and electronic grids on our planet if they are powerful enough.
While some solar cycles feature lots of activity, others can be relatively quiet. Scientists try and predict how active any given cycle will be, however, these efforts are limited by lack of understanding of the physical processes taking place in the Sun. Nevertheless, Wallace provides a prediction for the latest solar cycle.
“We’ll see the peak sometime in the summer of 2025, 115 sunspots plus or minus 10 in that period,” Wallace said. “It’s a long-term prediction and the future will tell how well this prediction went.”
While there is much we don’t know about the Sun, recent scientific endeavours such as NASA’s Parker Solar Probe are helping to cast new light on our star. The probe has travelled closer to the Sun than any other spacecraft, coming within 26.55 million miles of the star’s surface.
Earlier this year, astronomers released astonishing images of the Sun’s surface—captured by the Inouye Solar Telescope based on the Hawaiian island of Maui—providing an unprecedented view of our star.
“These are the most detailed images of the Sun ever taken,” Claire Raftery, a spokesperson from the NSF’s National Solar Observatory (NSO)—which built and operates the Inouye observatory—previously told Newsweek.
“They show features as small as 30 kilometers [19 miles]. For comparison, the previous largest publicly funded solar telescope could see features 160 kilometers [99 miles] in size, so that is more than a factor of five better.
“We are, for the first time, able to resolve detail in the smallest features of the Sun’s magnetic field. These tiny bright specks are thought to channel energy up into the outer layers of the solar atmosphere called the corona,” Raftery said.