To divide
The sun becomes more active and releases charged plasma into space. One plasma cloud “cannibalizes” a second one – and it should reach Earth soon.
FRANKFURT — The sun’s activity changes in a roughly eleven-year cycle, the so-called sunspot cycle. Currently, the sun is approaching the maximum of its activity, which should be reached in 2024 or 2025, depending on the calculation. You can already clearly see that the sun is becoming more active: solar storms repeatedly hit Earth and trigger the northern lights.
A so-called “cannibal” is currently on its way to Earth: A coronal mass ejection (CME) – a large, fast-moving cloud of magnetized plasma – has been ejected from the sun and captured and “cannibalized” by a second, faster CME. A large plume of plasma is now heading towards Earth from the Sun and, according to calculations, could reach it on July 18th.
Solar storm can cause auroras on Earth
If such a solar storm hits Earth’s magnetic field, geomagnetic storms can arise. These are disturbances in the Earth’s magnetic field, which can also be felt at greater distances from the poles in the form of beautiful northern lights.
The first solar flare occurred on July 14 in sunspot AR3370, according to Space.com. A second, faster CME was ejected from the larger sunspot AR3363 the next day. A simulation by NOAA’s Space Weather Prediction Center shows the second solar storm catching up and “cannibalizing” the first. The new, larger cloud of plasma continues to race toward Earth, where it will likely impact the magnetic field on July 18.
“Cannibals”: the second solar flare “cannibalizes” the first
“Cannibal” CMEs are rare because two consecutive solar flares must be precisely aligned and require specific velocities. In recent years, however, some have been observed – for example, in November 2021, a “cannibal” triggered one of the first major geomagnetic storms of the current solar cycle. As the Sun approaches sunspot maximum, CMEs are also more likely to “cannibalize” each other simply because more solar flares are occurring.
Experts originally predicted that the 25th sunspot cycle would peak in 2025 and become weaker than previous cycles. However, data has shown for some time that the maximum could be reached sooner. The number of sunspots – the darkest, coldest spots on the sun – is an indicator of how far along the solar cycle is. But already in December 2022, the sun reached the sunspot record in eight years. In 2023, experts counted more than twice as many sunspots as the American space agency Nasa had predicted.
A solar storm hitting Earth can cause massive damage. But most solar storms miss Earth. (archive image) © imago/ZUMA Wire
Number of sunspots is higher than predicted
And sunspot numbers remained high for the next few months as well—the number of observed sunspots has exceeded the number of predicted sunspots for 27 straight months, reports LiveScience. According to the science portal, several experts are now of the opinion that the maximum of the current sunspot cycle begins ahead of schedule.
Observing the sunspot cycle is important because solar storms not only bring beautiful auroras to Earth, they can also be dangerous. For example, satellites in orbit around Earth can experience problems due to charged solar plasma. Planes are diverted during predicted solar storms and radio communications can be temporarily lost. Particularly violent solar storms can also affect Earth’s infrastructure. These are primarily electrical devices, but Internet infrastructure can also be affected.
The Carrington Event was the largest scientifically observed solar storm
In 1859, the largest scientifically observed solar storm hit Earth, the so-called Carrington event. At that time, auroras could be seen in Rome and Hawaii – a rare sight because auroras are usually concentrated at the poles. At that time, telegraph lines were particularly affected: they gave off sparks and set the paper on fire. Just because electricity was not widespread at that time, the effects of the solar storm were limited.
In 2013, a study determined the impact a Carrington-magnitude solar storm would have on the United States. The result was alarming: according to the study, 20 to 40 million people in the US could be left without electricity for up to two years, and the economic costs would reach 2.6 trillion dollars in the US alone.
Carrington-magnitude solar storm narrowly missed Earth in 2012
In July 2012, a solar storm apparently comparable in magnitude to the Carrington event just missed Earth. Experts believe that the 2012 solar storm may have caused large-scale power outages. He would have “paralyzed everything that is connected to an outlet”, NASA wrote at the time.
Earth doesn’t have much to fight the approaching solar storms. Currently, the defense is mainly based on the observation and study of the sun. Solar probes such as NASA and Esa’s “Solar and Heliospheric Observatory” (Soho) and NASA’s “Stereo-A” probe observe the sun from space. If a coronal mass ejection has occurred, experts can predict its arrival on Earth – depending on the velocity, there are 12 hours to a few days before the plasma reaches Earth’s magnetic field.
During this period, vulnerable infrastructure can be protected, for example by controlling power grids properly, leaving planes on the ground or switching satellites to safe mode. Errors in satellite navigation can then be corrected and aircraft can be re-routed or grounded. Currently, there is nothing more that can be done to protect Earth from solar storms. (tab)