A leggy evergreen looms over a stretch of Arctic boreal forest as light from the aurora borealis paints the night sky emerald green.These natural fireworks shows, also called the northern lights, occur when solar wind—electrically charged particles blasted from the sun—collides with atoms in the upper atmosphere over the Earth's magnetic poles.

一株常青植物在北极圈的北方针叶林中独树一帜，隐现在被北极光染成翠绿色的天空下。这种天然的烟花表演，称为极光。太阳中的带电粒子爆发形成太阳风，当太阳风与地磁极上空的高层大气中的原子碰撞时，便产生了极光。