They are one of the most powerful eruptions on the surface of the sun, and on April 17, NASA’s Solar Dynamics Observatory captured one in 4K.
WATCH: Powerful solar flare seen in 4K
Solar flares originate from sunspots. These much cooler parts of the sun have complex magnetic fields. Think of the sun’s magnetic field like a looped rubber band. One end represents the south pole; the other, the north. As the sun rotates, the magnetic loops wrap tighter and tighter, making them twist like an elastic band. Suddenly the stored energy releases in the sunspot area and – bam! – you have a solar flare.
READ MORE: How solar storms could leave us in the dark
The strength of solar flares are measured on a scale from weakest to strongest : C, M and X. Each letter is a 10-fold increase in energy output.
The April 17 solar flare was an M6.7.