
Solar flares and sunspots —
NASA's Solar Dynamics Observatory, which observes the sun 24 hours a day, captures this image of an X-class solar flare at 7:42 a.m. ET Tuesday, June 10. X-class flares are the most powerful. Check out more images of recent solar flares and related activity:

Solar flares and sunspots —
NASA shows this second flare, which appears as a bright flash on the left side of the sun, shortly after it peaked at 8:52 a.m. ET on June 10. It was less powerful than the first flare that day.

Solar flares and sunspots —
A coronal hole, almost square in its shape, is one of the most noticeable features on the sun on May 5-7. A coronal hole is an area where high-speed solar wind streams into space. It appears dark in extreme ultraviolet light, as there is less material to emit in these wavelengths. Inside the coronal hole, you can see bright loops where the hot plasma outlines little pieces of the solar magnetic field sticking above the surface.

Solar flares and sunspots —
A large active region gave off warning signs as a possible source of powerful solar storms. It already shot off two smaller flares on January 2, as shown here in a wavelength of extreme ultraviolet light.

Solar flares and sunspots —
This image from the Solar Dynamics Observatory shows the sun at 12:45 p.m. ET on July 12, 2012, during an X1.4 class flare. The image is captured in the 304 Angstrom wavelength, which is typically colorized in red.

Solar flares and sunspots —
This image combines two sets of photos of the sun on July 12, 2012, to give an impression of what the sun looked like shortly before it unleashed an X-class flare.

Solar flares and sunspots —
NASA was watching when this trio of large sunspots formed on the eastern limb of the sun in 2012. The sunspots released several medium solar flares while moving across the face of the sun.

Solar flares and sunspots —
A very large filament became unstable and erupted June 27, 2012, as seen by the STEREO Ahead spacecraft in a wavelength of extreme UV light.

Solar flares and sunspots —
This active region of the sun could not contain itself as it popped off over a dozen flashes, minor eruptions, and flares over almost two days -- June 27 through 29 -- in 2012.

Solar flares and sunspots —
Two areas of dark plasma that were close together danced and entwined with each other over a one-day period March 27 and 28, 2012. The dark plasma, seen in profile, was somewhat cooler and therefore darker than the material around it.

Solar flares and sunspots —
This close-up view reveals magnetic forces at work as they pull plasma strands this way and that before gradually breaking away from the sun November 14 and 15, 2011.

Solar flares and sunspots —
Sunspots, which are cooler, darker areas of intense magnetic activity, are most often the source of solar storms. Here the sun's lower atmosphere is observed in extreme ultraviolet light July 17 and 18, 2011.


