NASA’s Solar Dynamics Observatory captured these images of solar flares — seen as the bright flashes in the top right — on April 23 and 24, 2026. The images show a subset of extreme ultraviolet light that highlights the extremely hot material in flares and which is colorized in in gold and blue on the left and teal on the right. Credit: NASA / SDO Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. The sun is an incomprehensibly gigantic, constantly roiling nuclear furnace —but some days are even busier than others. Based on data collected by NASA’s Solar Dynamics Observatory , our solar system’s central star recently fired off not one, but two impressive X-class flares within hours of each other. The sun emitted an initial X2.4 solar flare at 9:07 p.m. EDT on April 23, followed by an X2.5 sibling of extremely hot, charged energy at 4:13 a.m. EDT the next morning.…