They are red, green, sometimes yellow or purple. The appearance in the night sky enchants onlookers. In our latitudes they are usually rarely seen. But this year they also appeared in the night sky over Germany: northern lights. Your starting point is around 150 million kilometers away.
Will the celestial phenomena also be visible next year?
Experts are largely certain: yes. According to the German Aerospace Center (DLR), further sightings can be expected in Germany next year, including further south under favorable conditions. An expert from the Max Planck Institute for Solar System Research in Göttingen, Natalie Krivova, does not want to rule this out either.
“The sun is obviously approaching maximum activity.” This opinion is shared by the Friends of Celestial Science, which has its own observatory for observing the sun in Bad Salzschlirf in eastern Hesse. “We firmly assume that they will still be visible next year,” says Michael Passarge from the club.
Why can the northern lights be seen further south right now?
The sun is responsible for this. There are eruptions on the star, which result in a so-called coronal mass ejection towards Earth, which consists of electrons, protons and certain atomic nuclei. This sunspot activity peaks on average every eleven years.
“We can’t say whether we have already reached the maximum. It may be that activity will continue to increase,” says Krivova. In the opinion of the circle of friends, this maximum has probably not yet been reached and the so-called spot activity of the sun has increased significantly this time. The DLR also believes that the current sunspot cycle will reach its maximum in the coming year.
How are the northern lights created?
The mass ejections thrown towards Earth race through the solar system and hit the Earth. Because components of the plasma are electrically charged, they interact with the earth’s magnetic field and essentially compress it. Magnetic short circuits in the tail of the Earth’s magnetic field generate streams of particles into the polar regions, which stimulate the air particles to glow, which becomes visible as the glowing aurora borealis.
“It works like a fluorescent tube,” says Passarge. The high-energy particle stream hits the earth’s atmosphere and causes the air to glow. “The luminous color is determined by the molecules and atoms involved, as well as the energy of the photons emitted. Atomic oxygen emits green-yellow or red light, while molecular nitrogen causes blue-violet or deep-red glow,” says the DLR.
At what latitudes can these lights occur?
That depends on the strength of the solar flare. According to DLR, the following generally applies: “The stronger the geomagnetic storm, the further the aurora zones move equatorward. In the extreme case of the Carrington Event of 1859, auroras could even be observed in Hawaii and the Caribbean.” Typically, auroras would occur in two oval-shaped bands around the geomagnetic poles of the northern and southern hemispheres, typically at least ten degrees of latitude above the northern tip of Germany.
Are northern lights dangerous?
Not the northern lights themselves. The earth is largely protected by the magnetic field. Depending on their strength, however, the high-energy particle streams can be dangerous. According to Krivova, during strong solar storms there could be damage to satellites, telecommunications could be affected and there could also be power outages.
When is the best time to see the Northern Lights?
“If possible during the new moon,” says Passarge. The best seasons are spring and autumn.
