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Sun entered into Solar Cycle 25! But what are Solar Cycles?

Solar Cycle 25 started in 2020!

Many times we all have heard about “solar activity”, especially when it is about sunspots or flares that some space agency has spotted and is later on broadcasted on the news. This activity changes with the Sun´s cycle.

Solar cycle is a process in which the Sun´s magnetic field flips its north and south poles and takes place every 11 years approximately. The Sun is, in terms of number of atoms, about 90% made from gas, extremely electrically-charged hot gas in movement and therefore generating a magnetic field.

In 2020 a new solar cycle started, known as Solar Cycle 25, while cycle 24 took place between 2008 and the starting of current cycle 25 in 2020. NASA and NOAA co-sponsor the Solar Cycle 25 Prediction Panel, which declared the start of the new current solar cycle while announcing cycle 24’s minimum in December 2019.

As the Sun´s magnetic field change, so will do its activity, and actually the minimum and maximum activities are spotted at the beginning and middle of its cycle, respectively, as can be seen in next figures. Therefore, sunspot tracking is one of the ways to track solar cycles. In fact, the greater number of Sun sunspots, as well as most energy bursts and eruptions, are caused while changes in Sun’s magnetism, and actually it is at the height of its cycle, the solar maximum, when the Sun’s magnetic poles flip.

Figure: previous Solar Cycle 24, evolution of the Sun in extreme ultraviolet light from 2010 through 2020, as seen from the telescope aboard Europe’s PROBA2 spacecraft.

Figure: Differences between solar maximum and minimum activity, notice the difference between solar activity during Solar Cycle 24 at the solar maximum (left side, April 2014), and solar minimum (right side, December 2019).

Solar activity such as flares or eruptions send extremely powerful energy bursts into space and many times this activity is visible from Earth in Auroras, which are the result of the interaction between solar activity and Earth’s magnetic field. However, also radio communications and satellites can be affected due to solar activity: communication links could be damaged, as well as satellite electronics, astronauts’ spacewalk, space programmes as Artemis or even your position that Google Maps is reporting in our smartphones! Yes, accuracy in GPS, as in satellite-based positioning in general, is strongly related to solar activity.

It is of extreme importance to monitor space weather since it impacts our lives as well as technology which is present in everyday life. According to Jake Bleacher, NASA’s Human Exploration and Operations Mission Directorate, “there is no bad weather, just bad preparation”. This phrase is also used in northern countries when referring to their respective weathers and seasons and can be effectively extrapolated beyond our atmosphere. Bleacher continues “space weather is what it is, our job it to prepare”. Therefore, space weather actions must be taken and NOAA provides predictions and satellites for real-time monitoring.

It is really interesting to learn new things and maybe today you got to know what Solar Cycles are and that we have just started a new one! At the same time, weather monitoring is of vital importance both below and above our atmosphere.

Personally, I am more focused into satellite navigation and know that solar activity is an important actor in position accuracy but also for satellite electronic devices. Furthermore, while space exploration and communication research are my other two favorite topics,  sometimes we forgot that space exploration also involves space weather, which is an important topic that I really enjoyed researching in. Definitely newer posts in space weather will come in the future!

Thank you for reading!


NASA. Solar Cycle 25 Is Here. NASA, NOAA Scientists Explain What That Means
NASA. Our Sun.
NASA. What Is the Solar Cycle?
NASA. Does the Solar Cycle Affect Earth’s Climate?.