Aurora Over Quebec
Last week's northern lights—which lasted a few days—were products of a large burst of plasma, or charged gas, from the sun known as a coronal mass ejection. A NASA orbiter called the Solar Dynamics Observatory saw last Sunday's eruption, which was aimed directly at Earth and sparked predictions of a shimmering sky show.
Now it seems aurora fans may be in for another treat: A solar flare spotted Saturday by NASA's Solar and Heliospheric Observatory was even more powerful than the previous eruption. Although this time the bulk of the plasma burst isn't aimed right at Earth, scientists say it could still trigger another round of colorful auroras.