Looking like a crooked frown, SDO captured this image of a solar filament stretching across the lower half of the sun on Feb. 10, 2015.
A filament stretches across the lower half of the sun in this image captured by NASA’s Solar Dynamics Observatory on Feb. 10, 2015. Filaments are huge tubes of relatively cool solar material held high up in the corona by magnetic fields. Researchers simulated how the material moves in filament threads to explore how a particular type of motion could contribute to the extremely hot temperatures in the sun’s upper atmosphere, the corona. Credits: NASA/SDO