Intense solar storm, perfect weather: Auroras over all of Germany
During the night leading into Tuesday, a strong solar storm caused northern lights to appear far south. The phenomenon could be admired throughout Germany.
(Image: Dirk Knop)
An unusually strong geomagnetic solar storm caused auroras to be visible across Germany during the night. Recordings of the celestial spectacle were even received by the German Weather Service from the foothills of the Alps and from Austria. Responsible was a geomagnetic storm of the second-highest level G4, whose outer reaches reached Earth in about 25 hours. This is extremely fast; it normally takes several days. Despite the short advance warning, many people observed and even photographed the spectacle, also thanks to the clear starry sky. However, the situation had already calmed down again around midnight.
“We had a stronger eruption from the sun, and it has now reached us,” explained meteorologist Markus Bayer from the German Weather Service to the dpa news agency. This caused particles from the sun to be hurled towards Earth. Here, they were directed by the Earth's magnetic field towards the poles, where they penetrated the Earth's atmosphere. “In the upper layers of the atmosphere, the charged particles collide with air molecules and excite them to glow.” Normally, the auroras created this way are therefore primarily visible near the poles. As soon as it gets more intense, they can also be seen further south (or north in the Southern Hemisphere).
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The solar storm occurred during the particularly strong 25th solar cycle, which has passed its peak. Just a few months ago, a research group pointed out that this is part of a longer-term awakening of our home star, which is causing unexpectedly high activity. Previously, everything had actually indicated that the sun had entered a longer phase of low activity. In the worst case, a particularly active sun – one with many sunspots and large surface eruptions – can damage technical systems such as satellites or even become a danger to astronauts. A particularly strong solar eruption could even trigger an “Internet Apocalypse.”
That the sun goes through an approximately eleven-year cycle in its activity has been known for more than 200 years. These were traced back by the Swiss astronomer Rudolf Wolf in the 19th century to the year 1749, the maximum of the so-called 0th cycle. Meanwhile, the eleven-year cycle has been confirmed without gaps for the past 1000 years using tree rings and traced back to the year 969. At the same time, however, the sun is undergoing longer-term changes that cause activity to increase or decrease independently of the cycles. For example, for reasons yet to be fully understood, the sun was at its least active in the 17th century and again at the beginning of the 19th century.
(mho)
