"The sun is slowly waking up": Solar activity rising unexpectedly since 2008
It was actually assumed that the sun had been going through a particularly quiet phase since 2008. However, according to two researchers, this is not the case.
Overview of two solar cycles
(Image: SOHO (ESA & NASA))
Solar activity has risen continuously for 17 years, and if this trend continues, solar storms and solar flares could become more frequent regardless of the solar cycle. This has been determined by two NASA researchers who have evaluated various developments in the behaviour of our sun. According to their findings, a trend of decreasing solar activity that began in the 1980s ended in 2008, but the low level expected at the time did not materialize. Instead, the sun changed course and became increasingly active. This could have consequences for more than just space travel in the future.
It has been known for more than 200 years that the sun goes through an approximately eleven-year cycle of activity. This was calculated by the Swiss astronomer Rudolf Wolf in the 18th century back to the year 1749, the maximum of the so-called 0th cycle. In the meantime, the eleven-year cycle has even 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 undergoes long-term changes that ensure that its activity increases or decreases independently of the cycles. For example, the sun was at its most inactive in the 17th century and then again at the beginning of the 19th century for reasons that are as yet unexplained. At the beginning of the space age, it was then more active than it had been for a long time.
Solar activity with concrete consequences on Earth
It was already known that the current 25th solar cycle was stronger than expected. It also reached it's maximum earlier. However, the two NASA researchers have now confirmed that this is part of a larger trend: "The sun is slowly waking up," says study leader Jamie Jasinski from NASA's Jet Propulsion Laboratory. Overall, this was a surprise, as everything had actually indicated that the sun had entered a longer phase of low activity. He and Marco Velli determined that this was not the case using data on the solar wind and magnetic field, among other things. They have published their research in the Astrophysical Journal Letters.
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The continuous observation and prediction of solar activity is not only important for the study of our sun; phases of particularly high activity can have very specific consequences on Earth. In the worst-case scenario, a particularly active sun – with many sunspots and large eruptions on the surface – can damage technical systems such as satellites or even pose a danger to astronauts. A particularly strong solar flare could even trigger an "internet apocalypse". In addition, just a few months ago, a research team discovered that so-called superflares on our sun are much more common than assumed. These are gigantic eruptions on the sun with potentially devastating consequences for modern infrastructure.
(mho)
