Danger for satellites

Astronomers expect further strong solar storms

On Wednesday, there was an eruption (marked in red) of magnitude X8.7 from a sunspot group called AR 3664.

(Bild: NASA/SDO)

Things are still boiling on the sun. While satellite operators are still analyzing the consequences of the weekend's major solar storms in detail, an even larger eruption of magnitude X8.7 from the same huge sunspot group called AR 3664 (image above) followed on Wednesday.

However, our central star has continued to rotate in the meantime and AR 3664 has moved slightly to the side so that, from an astronomer's point of view, only part of the ejected solar material (also known as CME) should hit the Earth during eruptions.

ISS space station could be affected 
Space travelers on the ISS space station could also be affected by solar storms. "The decision as to whether the ISS crew has to go into a protected area during a solar storm depends on the strength of the solar storm and the potential radiation exposure for the crew," ESA astronaut Alexander Gerst told the German press agency dpa. According to NASA, there was no direct danger to the ISS crew during the solar storm at the weekend.

The space travelers on the ISS space station (pictured) can also be affected by solar storms.

(Bild: NASA)

The sun's activity fluctuates in an approximately eleven-year cycle. The current cycle is currently at its maximum. Such a cycle lasts a few years, during which there are always relatively many solar flares. "On Tuesday, we saw the strongest eruption of the entire cycle so far," said Sami Solanki from the Max Planck Institute for Solar System Research in Göttingen. It is not possible to say whether the peak of the current maximum has already been reached.

Maximum willlast another two years
The current solar cycle is already somewhat stronger than the previous one, explained astronomer Volker Bothmer from the University of Göttingen. He estimates that the maximum will last for about two more years and then fall off. He could not predict whether the activity would become even stronger or not. According to NOAA data, the number of sunspots is currently nowhere near as high as at the peak of the maxima in the late 1950s and early 2000s.

According to the US National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC), Tuesday's large eruption also produced the strongest flare - a kind of giant flash of light (pictured below in different frequency ranges) - of the current solar cycle.

Flare led to failure of radio signals
The radiation from the flare led to failures of high-frequency radio signals throughout America. Amateur radio operators, aviators and sailors may have noticed a sudden loss of signal at high frequencies. Geomagnetic effects such as auroras were considered unlikely.

Malfunctions in several satellites
The major solar storm last weekend not only caused colorful auroras in numerous regions around the world, but also malfunctions in several satellites, for example at the European Space Agency ESA.

"ESA satellites are also affected, but we are still collecting data," confirmed an ESA spokesperson. She said that some satellites orbiting the Earth had drifted slightly off course due to the change in atmospheric drag, which always affects them. Course corrections should now bring them back on track.

Partial GPS failures in the USA
Several farmers in North America complained about a failure of the satellite-based US navigation system GPS, as reported by the "New York Times", among others. They had to interrupt their sowing because they were using the system to work in the fields.

According to a report in Nature magazine, internet connections from Starlink, which belongs to the space company SpaceX and has thousands of satellites, were also temporarily disrupted. The instruments of NASA's Chandra X-ray observatory were temporarily stowed away to protect them, it is said.

Even if the sunspot group AR 3664 disappears behind the sun as seen from Earth, astronomers can continue to analyze it thanks to the ESA space probe "Solar Orbiter". They expect that a coronal mass ejection (CME) could collide with Mars in the near future.