On Tuesday the sun erupted with the largest solar flare since last August, categorized as an X5.4. The above image, captured by NASA's Solar Dynamics Observatory, shows the flare in multiple wavelengths (94, 193, 335 angstrom). Another, smaller flare exploded about an hour later. The coronal mass ejections produced by the flares may cause electrical, radio, and GPS disruptions today. The Atlantic's video channel has footage of the solar activity here.

Below, recent Pictures of the Day:

Image: NASA.