Amazing Science Images You Must See
Auroras Over America
Undulating high over Quebec and Ontario, the northern lights outshine city lights on Oct. 8, 2012. The strong aurora borealis resulted from a sun stormthree days earlier that sent solar particles on a collision course with Earths atmosphere. The interaction excites oxygen and nitrogen molecules 60 to 250 miles (100 to 400 kilometers) up, releasing photons, or light particles.