A Strange Coincidence

About every eleven years the Sun completes a sunspot cycle. Every 11.9 years Jupiter completes its orbit of the Sun. Coincidence? Maybe, but there is compelling evidence to suggest that Jupiter and the sunspot cycle are linked.

Image 1.0  Sunspots at the beginning of the 2017 Total Solar Eclipse

The Solar Sunspot Cycle

The solar maximum (the period when the Sun has the maximum sunspot count) of last six cycles occurred in 2012, 2001, 1990, 1979, 1968, and 1957. In each case, the solar maximum extended over many months, but by selecting a common date within the period, (e.g.; June 1st,) the eleven year period becomes apparent (SEE Graphic 1.0)

Graphic 1.0 The Eleven-Year Solar Cycle using a Common Date (June 1st)

It is important to note that the eleven-year cycle applies to the maximum sunspot activity. Solar minimums tend to vary significantly from cycle to cycle; however, solar maximum activity is usually reliable within plus or minus six months.

Jupiter’s Solar Cycle Precession

The question is, where is Jupiter in relation to the Sun during the solar maximums? The answer is simple. For the last six solar maximum cycles, Jupiter has been approximately twenty-five degrees (25°) further back in its orbit than the previous solar maximum. 

Graphic 2.0 The position of Jupiter in its Orbit for the Recent Solar Maximum Cycles and the upcoming cycle (Planets reflect orbital positions for 25 FEB 2019)

The idea of a connection between Jupiter’s orbit and the solar cycle has been traditionally scoffed at by astrophysicists; however, as more is understood about the dynamics of the Sun’s influence beyond the visible solar atmosphere, scientists are less eager to ignore the possibility. A 2016 German study suggests Jupiter, Venus, and Earth may all play a role in sunspot activity.

If there is a connection between the position of Jupiter and the solar maximum, it raises the question of why? Is it a gravitational link, or is it an electromagnetic link? Why does the solar maximum occur when Jupiter is approximately 25° further behind its position of the last solar maximum? Answers to these questions will certainly lead to more questions.

The answers may come soon. In the meantime, Jupiter is raising some interesting questions.