Our Tempestuous Sun: Part 3

ur Sun’s Invisible Magnetic Fields – Previously, we learned that the stirring and convection of ultra-heated plasma in our Sun’s inner layers – the solar dynamo – create its magnetic fields that are invisible to our eyes!  How then do scientists know the sun has magnetic fields you wondered?   We’re going to tell you in this issue.  Scientists confirmed their suspicions about the sun’s magnetism by conducting experiments on earth using bar magnets.  They discovered that charged particles moved filings, and that these filings structured themselves around the bar magnet in a particular way.  The visualized experiment showed that the filings arranged themselves around the bar magnet, curving, arching and extending outward, see, Figure 1, left, validating solar scientists’ theories of how the sun works, based on their  observations of its atmosphere.

Figure 1. Visualized iron filings show bar magnetic field lines.

With this new information confirming their observations, scientists determined that that flowing charged particles they saw, the sun’s plasma, “naturally create magnetic fields, which have an additional effect on how the particles move.”[1]  So, the sun is akin to a big magnet, and scientists’ experiments led them to logically conclude that a magnetic field is the description of the force a magnetic object exerts in the space surrounding the magnetic object.”[2]; or [a] magnetic field is an invisible force field created by a magnet or as a consequence of the movement of electric charges (flow of electricity).”[3].  The sun’s magnetic fields channel the plasma (charged particles) solar scientists observe streaming from the sun’s corona. 

[1] Sarah Frazier NASA’s Goddard Space Flight Center, Greenbelt, Md.; https://www.nasa.gov/feature/goddard/2016/understanding-the-magnetic-sun

[2] NASA, Southwest Research Institute, IBEX (Interstellar Boundary Explorer), Principal Investigator Dave McComas; http://ibex.swri.edu/students/How_does_the_Sun.shtml; see also, “A magnetic field is an invisible force field created by a magnet or as a consequence of the movement of electric charges (flow of electricity). https://ec.europa.eu/health/scientific_committees/opinions_layman/en/electromagnetic-fields/glossary/mno/magnetic-field.htm

[3] Source: GreenFacts; https://ec.europa.eu/health/scientific_committees/opinions_layman/en/electromagnetic-fields/glossary/mno/magnetic-field.htm#:~:text=A%20magnetic%20field%20is%20an,charges%20(flow%20of%20electricity).

Sunspots and Magentic Fields – A sunspot is a dark blotch on the sun.  The Chinese and the Aztecs were the first to observe, note, and record sunspots on the sun’s surface.  Accordig to Patrick J. Kiger in “How Sunspots Work”[1] the Chinese were the first to make a written record of a sunspot” in “28 B.C.,” ibid.    They recorded their observations that “the sun was yellow at its rising and a black vapor as large as a coin was observed at its center.” Ibid.  Clear references to the sun’s dark spots. 

[1] The History of Sunspots | HowStuffWorks,

Figure 2: Images courtesy SOHO (NASA & ESA) and the Royal Swedish Academy of Sciences

Kiger also informs us that the Aztecs observed the sun prior to the arrival of the Spanish and that “their creation myth featured a sun god with a pockmarked face” ibid, which is a reference to the dark spots they observed.  Later in the late 1500s and early 1600s curious scientists observed not only that dark spots were on the sun’s surface, but that they appeared, disappeared and reappeared approximately every two weeks, suggesting that the sun rotates!   

Figure 3: Sunspots Generated by a Magnetic Field; Nature of the Universe.

Sunspots are disturbed magnetic fields that are common features of the sun[1].  Sometimes appearing in pairs, each sunspot pair has the opposite polarity, forming the solar magnet.[2]  Plasma streaming from the sun is directed along the sun’s invisible magnetic fields, creating the solar atmosphere we observe and experience.  In our next issue, we will delve into the types of solar weather that stream towards earth, how it affects our environment and the precautions we take against extreme solar weather.  See you then!! 🙂

[1] https://scied.ucar.edu/learning-zone/sun-space-weather/surface-of-the-sun

[2] Magnetograms (stanford.edu)\

Figure 4: Coronal loops above a sunspot pair;Eclipse 2017 Coronal Prediction (stanford.edu)