We have officially entered a new solar cycle!
The sun has entered a new cycle. Don’t beat yourself up if you’re a stargazer and haven’t noticed anything. There were no flashes of light, no cosmic trumpets. Just an appearance of low-temperature shadows called sunspots at high latitudes.
There have been 24 of these cycles since observations were first recorded in the mid-18th century. And, according to a panel made up of experts from NASA and the National Oceanic and Atmospheric Administration (NOAA), December 2019 marked the start of number 25.
Ever since we started to track the Sun’s dark blemishes in earnest, humans have noticed a pattern of quiescence and temper that repeats roughly every 11 years.
However, despite centuries of careful recording of these 11 year cycles, we still don’t have the mechanisms behind these cycles fully worked out. Periodicity in stars is a common phenomenon. There are a variety of pulsating objects that seem to flare and darken at intervals you could almost set your watch by.
The best we can determine for our own Sun’s patterns has to do with changes in its magnetic fields, which are in turn driven by complex currents of flowing plasma deep within.
Exactly what pushes and pulls these currents in such a rhythmic way is the part we need to figure out, but there’s a temptation to link it with a similar periodicity in planetary orbits.
While the cycle of highs and lows takes place over 11 years, it is more accurately a reflection of a larger 22-year cycle defined by a complete overturn in the Sun’s polarity. Every 11 years the poles swap, returning to place at the end of the next loop.
Monitoring these transitions can help us better predict space weather, which is dictated largely by outbursts of charged plasma and radiation that can ferociously blow out into space, especially during solar maximums.
The Sun consists of only a few elements, of which hydrogen is predominant at around 72%, and helium at about 26%, with the other elements accounting for progressively smaller amounts, such as oxygen, carbon, neon, nitrogen, magnesium, iron and silicon.