What do 10 years mean for our 4.6 billion years? Sun? Probably as much as the last millionth of a second meant to you. Still, every decade our old sun burns is a decade of turbulent, sometimes violent change, a fact that becomes wonderfully evident in a new time-lapse video from NASA’s Solar Dynamics Observatory (SDO).
In the awesome video, titled “A decade of sunshine“Astronomers compiled 425 million high-definition images of the sun, taken once every 0.75 seconds between June 2, 2010 and June 1, 2020. Each second of the video represents a day in the life of the sun , and the entire decade goes by in about 60 minutes (though you can see our featured 6-minute reel above).
During that decade, the sun undergoes a radical change, slowly bubbling with huge magnetic waves known as Sunspots, which peaked around 2014 before disappearing again. The stillness of the sun was not a surprise; every 11 years or so, the magnetic poles of the sun suddenly change places; North becomes south, solar magnetic activity begins to decline, and the sun’s surface begins to resemble a calm sea of yellow fire. This period of relative calm is called solar minimum (and we are currently in the middle of one).
Halfway between the flip-flop of one decade and the next, however, a violent change occurs. Magnetic activity increases to a vibrating high, known as solar maximum, and the surface of the star undulates with gigantic sunspotsspanked sows magnetic field lines and bursts with plasma explosions known as solar flares. Each maximum reaches a maximum with the inversion of another magnetic pole, indicating the start of a new solar cycle.
These changes are difficult to detect from Earth with the naked eye (although solar maxima result in greater visibility auroras at lower latitudes around the world), but NASA’s SDO satellite clearly sees them while monitoring our star extremely ultraviolet light. These ultra-energetic wavelengths traverse the sun’s glare and reveal abundant magnetic changes in the sun’s outermost atmosphere, or corona. It is an impressive sight to see, even if the sun has probably already forgotten it.
Originally published in Living science.
