astronomy
Northern lights shine over parts of Germany
Impressive: Northern lights can be seen in the sky above Schillig in Lower Saxony. photo
© Markus Hibbeler/dpa
The northern lights are actually associated with the far north. But now they could also be admired in parts of Germany. A rare – if not entirely surprising – spectacle.
A rare celestial spectacle occurred in several federal states on Monday night: in parts of Saxony-Anhalt, Brandenburg, Schleswig-Holstein and Lower Saxony Several dpa reporters reported that the northern lights were visible. The night sky shone in different colors such as green, purple, yellow and red. The lights were particularly easy to see in rural areas.
Is the sighting in Germany something special? According to the German Research Center for Geosciences (GFZ), northern lights mostly occur in the far north between 60th and 70th parallel. For orientation: Oslo is just below the 60th parallel, the Norwegian city of Tromsö just below the 70th parallel. However, during strong solar storms, the northern lights can be seen further south.
In principle, the stronger the solar storms, the better the visibility in southern latitudes, explained a spokesman for the GFZ. The Kp index is a measure of the strength of a solar storm. A Kp index between 0 and 3 indicates low solar activity, with a Kp value of 9 there would be northern lights even over the middle of Germany – for example Dresden or Kassel. In very rare cases, these can also be seen from the Alpine region. The prerequisite for this is clear skies and a clear view to the north.
High-energy solar wind particles
The northern lights had already been spotted over Saxony-Anhalt a few days ago. At that time the Kp index reached a quite high value of 6.333. On Monday night the value was a maximum of 5.667. The value of 6 has already been exceeded 22 times this year. Values beyond 8 have only been reached three times, according to the GFZ spokesman. The 9 did not yet appear on the Kp index this year.
Relatively high values of the Kp index are currently not unusual, said the spokesman. As solar activity increases, such geomagnetic storms become more frequent. The play of light in the sky is triggered by so-called high-energy solar wind particles, which are thrown into space at high speeds by eruptions on the sun’s surface and hit the Earth’s magnetic field.
Back in April, a spokesman for the Institute for Solar-Terrestrial Physics at the German Aerospace Center (DLR) announced that the current increase in sightings was not entirely unusual. Approximately every eleven years, in a so-called solar cycle, there are phases with weak and strong solar activity. We are currently approaching a maximum. It is expected in 2025. Spring and autumn are statistically the best times of year to discover the Northern Lights in Germany.