Sun’s peak activity period could come year earlier and last longer than thought, scientists say

‘Significant change’ in Sun’s activity may come as good news for sky watchers ahead of next year’s solar eclipse

The Sun is expected reach the peak of its activity in 2024, a year earlier than previous estimates, scientists say.

This activity, known as “solar maximum”, in the current 11-year cycle will be between January and October 2024, according to the US National Oceanic and Atmospheric Administration (NOAA).

Earlier estimates suggested that the current Solar Cycle 25, which began in 2019, would peak in 2025.

“It’s a pretty significant change,” said Mark Miesch from NOAA’s Space Weather Prediction Center.

The 11-year activity cycle of the Sun is tied to the number of sunspots, which in turn are linked to the intensity of space weather, including solar flare activity from the star.

These are powerful bursts of energised plasma that come out of the star. They can interfere with the Earth’s magnetic field and cause damages to electrical grids, knock out satellites and even harm astronauts and space equipment if they are directed at the planet.

A previous panel convened by NOAA, Nasa and the International Space Environment Services (ISES) in 2019 predicted Solar Cycle 25 would be weak and peak in July 2025 at a maximum sunspot number of 115.

But a new revised prediction for solar activity during Solar Cycle 25 concludes that solar activity will increase more quickly and peak at a higher level than that predicted by the 2019 expert panel.

The updated estimate suggests Solar Cycle 25 will peak between January and October 2024, with a maximum sunspot number between 137 and 173.

“We expect that our new experimental forecast will be much more accurate than the 2019 panel prediction and, unlike previous solar cycle predictions, it will be continuously updated on a monthly basis as new sunspot observations become available,” Dr Miesch said.

Scientists have routinely warned that the world is not prepared for the danger posed by increased solar activity, as even minor space weather events of the past have had major impacts.

For instance, a small scale solar storm in February last year caused 38 of 49 SpaceX Starlink satellites to fail to reach their intended orbit. They instead burned up during their unplanned re-entry into the Earth’s atmosphere.

Researchers said improved observations and forecasts of space weather events can help avoid such satellite losses in the future.

The new prediction could also be good news for sky watchers who will likely anticipate looking at the Sun’s outer atmosphere during the total solar eclipse in April next year.

During total solar eclipses occurring amid the Sun’s peak activity, the star’s disk is completely blocked by the Moon, but its outer atmosphere, called the corona, will likely be more prominently visible.

“The Sun may put on a good show, with a particularly impressive corona – the extended outer atmosphere of the Sun that is only visible during an eclipse,” NOAA said in a statement.