The lofty goals of NASA's Artemis mission, to bring the first woman and next man to the Moon by 2024, are steaming ahead though whether it makes that date is yet to be seen. However, new research has unearthed an interesting pattern in the most energetic event released from the Sun – solar storms – that suggests sticking to the date may be rather important to avoid confrontations with extreme space weather.
The solar cycle of the Sun's magnetic field lasts for around 11 years. We are currently at the beginning of Cycle 25, the 25th cycle since humans started recording them. The solar minimum is the part of the cycle that has the least amount of activity, while the solar maximum – which is due for July 2025 – is the most active, causing the Sun's magnetic poles to flip, sunspots, and solar eruptions of particles.
The new study, reported in the journal Solar Physics, has found that solar storms will either occur before the maximum or after the maximum depending on if the cycle is an odd or even number. If the cycle is even, solar storms are more likely to occur early in the cycle, and if they are odd-numbered, like Cycle 25, extreme space weather is more likely to occur later ie after the maximum in 2025.
Solar storms affect space weather greatly. They can be a risk to satellites, spacecraft, and astronauts, so such a finding is a warning. Forays away from Earth’s protective magnetic field may come with extra risks depending on which cycle and what year is it.
“Until now, the most extreme space-weather events were thought to be random in their timing and thus little could be done to plan around them,” lead author Professor Mathew Owens, a space physicist at the University of Reading, said in a statement.
“However, this research suggests they are more predictable, generally following the same 'seasons' of activity as smaller space-weather events. But they also show some important differences during the most active season, which could help us avoid damaging space-weather effects.”
With this pattern in mind, we should expect more solar storms in the latter half of this decade and this could be a risk for the astronauts that will take part in the Artemis program. The researchers note that any major space missions planned beyond the next five years should take into consideration the higher risk of severe space weather between 2025 and 2030 and plan accordingly.
“These new findings should allow us to make better space weather forecasts for the solar cycle that is just beginning and will run for the decade or so. It suggests any significant space missions in the years ahead – including returning astronauts to the Moon and later, onto Mars – will be less likely to encounter extreme space-weather events over the first half of the solar cycle than the second,” Professor Owens said.