The Sun’s high temperatures causes these electrically-charged gases to constantly move around the surface of the Sun. Our star is a glowing ball of electrically-charged gas. To understand a solar cycle, it’s important to understand the Sun’s behavior. This split image shows solar maximum (April 2014) versus solar minimum (December 2019) which began Solar Cycle 25.Ĭredits: NASA/ SDO What Causes the Cycle of Solar Activity? At the end of the cycle, the solar activity fades and we reach the “solar minimum” again.At mid-cycle, the Sun’s sunspots peak and build to a very active, stormy “solar maximum.” This is when the north and south poles of the Sun flip!.At the beginning of the 11-year cycle, there are no or few sunspots and it’s called the “solar minimum.”.However, it has been as short as eight years and as long as 14 years. How Long is a Solar Cycle?Īs mentioned above, the average length of a solar cycle is 11 years.
Solar Cycle Sunspot Progression Note the progression of sunspot numbers in a solar cycle.
The change in polarity and reversal of the magnetic field has happened, on average, every 11 years over the past centuries. When the Sun is mid-cycle and reaches its peak, the Sun’s north and south poles flip! The south magnetic pole switches to north and vice versa. Ten Earth’s could be laid across its diameter. What Are the Northern Lights (Aurora Borealis)?Ī massive sunspot captured on Oct.
