Every 11 years or so, the Sun’s magnetic field completely flips. Monitoring this phenomenon is important, as it can damage technology and astronauts’ health.
Last Tuesday (15), scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA), confirmed the beginning of the 25th solar cycle.
According to experts, the solar minimum, when the star’s activities decrease, was observed in December 2019, indicating the beginning of the new stage.
“As we emerge from solar minimum and approach Cycle 25’s maximum, it is important to remember solar activity never stops; it changes form as the pendulum swings,” said Lika Guhathakurta, a scientist at NASA’s Heliophysics Division, in a statement to the press.
In each of these stages, the Sun goes through quieter and slightly more turbulent phases.
Solar flares and coronal mass ejections increase during the solar cycle, generating powerful explosions that send large amounts of energy and matter into space.
Why bother monitoring solar cycles?
Monitoring these cycles is important not only to understand how the Sun works, but also because these spikes in activity can affect life on Earth: solar flares can affect radio communications and interfere with power grids.
In addition, they can harm astronauts currently on the International Space Station (ISS).
For this reason, monitoring solar cycles is essential to protect satellites and astronauts, and to plan future space missions.
“There is no bad weather, just bad preparation,” noted Jake Bleacher, chief scientist of NASA’s Human Exploration and Operations Mission Directorate. “Space weather is what it is – our job is to prepare.”
Identifying a new solar cycle
To determine the beginning of a new solar cycle, the researchers analyze monthly data on sunspots, identifying their variations.
“It is only by tracking the general trend over many months that we can determine the tipping point between two cycles,” explained Frédéric Clette, one of the researchers.
Scientists expect the peak of this cycle to occur in July 2025. The strength of the cycle is expected to be below average, like the previous one – but that does not mean that there will be no risks.
“Just because it’s a below-average solar cycle, doesn’t mean there is no risk of extreme space weather,” said Doug Biesecker, a solar physicist at the NOAA’s Space Weather Prediction Center (SWPC).
“The Sun’s impact on our daily lives is real and is there. SWPC is staffed 24/7, 365 days a year because the Sun is always capable of giving us something to forecast.”