The sun is definitely hitting its usual ‘rebellious’ phase on its 11 year sunspot cycle, where it flares up at literally everything.
The biggest sunspot observed in 24 years has been releasing huge amounts of energy, in the form of X-class solar flares. In the past week this sunspot, designated AR 12192, has released 3 X-class flares, including a huge X-3.1 on Friday. NASA’s Solar Dynamics Observatory (SDO) has been watching the light show.
Okay so the Sun is blowing up, what does all this mean?
Let’s start with Sunspots. A sunspot is a place on the sun where there is a huge amount of magnetic activity. This activity can slow down convection currents in the solar photosphere and cool down a region of the sun. Now when I say cooling I’m still talking like 3000-4000 Kelvin, but that’s definitely less than the usual 5500 K. This cooling causes the region to appear dark and spotty. Hence the name sunspot.
A solar flare is a huge release of energy from a sunspot, similar to Trillions of Atomic Bombs going off at once. They are measured on a logarithmic scale based on their peak flux (Power per unit area) seen at Earth, and are characterized from weakest to strongest with the letters A, B, C, M, and X. After the letters, the classes are subdivided with numbers 1 to 9, with X2 being twice the power of X1, X3 is three times as powerful as X1, and so on. They also release a torrent of charged particles called a Coronal Mass Ejection, or CME. These particles reach Earth in under 36 hours and can do all sorts of damage to electronics in Space, and sometimes on the ground.
So you can imagine, three X class flares in a week in substantial. Still, the strongest one of the year was in February, where we saw a massive X4.9 flare.
Buy why have we seen so many powerful flares lately?
Answer: the 11 year Sunspot cycle. Every 11 years the sun hits a maximum level of activity, producing more sunspots and releasing more flares. Since roughly the year 1750 we’ve recorded the sun’s activity, and the cycle has come through like clockwork.
If you were wondering, the largest recorded solar flare of all time was in 1859, called the Carrington Event. This one was classed as an X40.
So why doesn’t all this release of energy and Coronal mass cause us to fry? The Earth’s magnetic field protects us, by funnelling the radiation to the poles, where it ionizes gas in the upper atmosphere, producing flashes of light that we lovingly call ‘Aurorae.’ Yup, the Northern (or Southern) lights.
So next time you see the Northern Lights, just think ‘Wow, that’s a huge explosion from the sun that would kill us all, except that the Earth’s magnetic field protects us and gives us a kickass light show instead’.