Auroras create green curtains of light August 4 over the Rupert River in Waskaganish (see map), a Cree Nation community in Quebec, Canada.
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.