Solar Activity: High Number of Sunspots in 20 Years
Sunspots are indicators of whether the sun is particularly active or not. Currently, there are a particularly high number of sunspots – the highest in 20 years. „We are currently at the peak of a relatively strong solar cycle,“ explains solar physicist Achim Gandorfer from the Max Planck Institute for Solar System Research in Göttingen to the German Press Agency. The cause of this is strong temperature differences.
Sunspots occur more frequently in an eleven-year cycle and then gradually disappear (solar sunspot cycle). Gandorfer states, „Whether we are already at the end of the cycle or if there will be another increase, it is currently impossible to say.“
The sun is a ball of gas mainly composed of helium and hydrogen. While its surface is around 6000 degrees hot, inside it is a blazing 15 million degrees with enormous pressure. This causes gases from the interior to swirl to the surface, sometimes resulting in huge eruptions. In some areas, the sun’s magnetic field prevents these gases from being expelled, causing the temperature of the matter to drop suddenly. This leads to the visibility of dark spots that are about 2000 degrees cooler than their surroundings, standing out from the rest of the sun’s surface. Gandorfer explains, „Although the spots are still very, very hot, they appear darker in contrast because the surroundings are hotter and brighter.“
Due to the sun’s high activity, the likelihood of solar eruptions increases. During these solar storms, billions of tons of high-energy particles are hurled into space, some of which can reach Earth. This can potentially cause damage to satellites. On the bright side, the Northern Lights become more visible as a result. Even in areas where they are not typically seen.
Since the invention of the telescope in the early 1600s, sunspots were first observed. They have been systematically documented since the mid-18th century.
