Sun's Crazy Active Cycle Could Mess With NASA's Artemis Moon Mission

The sun is ramping up for Solar Cycle 25's solar maximum at a faster rate than previously expected, which could have knock-on effects on future space missions, experts say.

At solar maximum, the sun has a lot more sunspots—dark-looking areas where the coronal magnetic fields are particularly strong—on its surface, which are associated with increased solar activity, including solar flares and coronal mass ejections (CMEs). If aimed at Earth, these can influence and disrupt electromagnetic communications and the power grid.

Our sun's activity follows roughly 11-year cycles, during which the sun's magnetic field flips, with the north and south poles switching places. The middle of this 11-year cycle sees the sun reaching its solar maximum, when it experiences increased numbers of sunspots and solar storms. Solar Cycle 25 marks the 25th cycle since we began recording sunspot activity in 1755.

solar storm
Stock image of the sun and solar flares. The sun has been more active than predicted at this stage of its cycle. iStock / Getty Images Plus

Despite only entering Solar Cycle 25 in December 2019, the sun's activity has quickly increased, exceeding predictions. According to NASA, this increased activity means that sunspots and subsequent solar storms will continue to increase until the forecasted 2025 solar maximum. According to spaceweather.com, the number of sunspots in May was the highest in almost eight years, and Solar Cycle 25 "is on track to outperform" Solar Cycle 24, which was an average cycle in terms of sunspot activity.

Scott McIntosh, deputy director of the National Center for Atmospheric Research, told Newsweek that the sun was producing more sunspots than usual this cycle, and hence was more active as a consequence.

The implications of this more active solar cycle may be that solar flares and CMEs increase in frequency. This can affect communications, which, with our increasing reliance on satellite technology, may have widespread impacts on Earth.

Additionally, future space exploration missions may also be impacted, as astronauts on spacewalks can be dangerously affected by the increased levels of solar wind radiation.

"Between Apollo 16 and 17 there was a huge space weather event that would have likely been fatal if astronauts had been on the moon at the time," Matthew Owens, a space physicist from the University of Reading in the U.K, told Technology Review.

Artemis, NASA's upcoming mission sending people to the moon for the first time since the Apollo program, is aiming to land astronauts on the moon's south pole by 2024. The next solar maximum, where solar storms are expected to be most ferocious, is forecasted for 2025.

"With activities like Artemis going on and increased exploration of Mars, the sun will factor more into the planning than it might have," McIntosh said. "Similarly, worries about the potential impact on GPS and/or the power grids will be getting more scrutiny and concern."

According to a study published in the journal Solar Physics in 2020, Solar Cycle 25 could have a "magnitude that rivals the top few since records began." The most active solar cycle ever was the 19th, from 1954 to 1965, which saw 285 sunspots within a single month in March 1958. Before the age of human space missions, Solar Cycle 19 still had impacts on communications, notably in February 1956 when a solar storm caused radio contact with British submarine Acheron to be lost.

If a solar storm or CME of large enough magnitude occurred during Artemis or other space missions, both the astronauts and their equipment could be in danger.

"Solar storm events and solar energetic particles are a very real risk for astronauts outside the protective envelope of Earth's magnetosphere," Dan Baker, a space physics researcher at the University of Colorado Boulder, told Technology Review. "However, I think that prudent steps can be taken to guard against the effects of such severe space weather. With an active and effective operational space weather alert and warning system, I believe the threats can be made manageable."