直接从(维基百科)(https://en.wikipedia.org/wiki/Aurora # Auroral_mechanism): >极光与太阳风相关联,一个流动的离子>从太阳不断向外流动。地球的磁场>陷阱这些粒子,其中许多旅游向两极>他们加速向地球的地方。这些离子和>大气原子和分子之间的碰撞导致能量释放的形式>极光出现在大圆圈周围的两极。极光更>频繁和光明在强烈的太阳活动周期的阶段当>日冕物质抛射太阳风的强度增加。> >极光产生的光子在地球上层>大气排放,超过80公里(50英里),从电离氮分子>恢复一个电子,和氧原子和氮分子>从激发态返回基态。碰撞电离>或兴奋的太阳风和磁层粒子>被注入下来,沿着地球磁场加速>行;激发发射光子的能量散失,或者通过>碰撞与另一个原子或分子:> > * * * * *氧气排放:绿色或棕红色,取决于的能量吸收。> > * * *氮排放* *:蓝色或红色;蓝色如果原子恢复电子电离后,红色如果从激发态回到基态。> >氧是不寻常的回到基态:它可以>四分之三的第二个发出绿光,两分钟>发出红色。 Collisions with other atoms or molecules absorb the > excitation energy and prevent emission. Because the very top of the > atmosphere has a higher percentage of oxygen and is sparsely > distributed such collisions are rare enough to allow time for oxygen > to emit red. Collisions become more frequent progressing down into the > atmosphere, so that red emissions do not have time to happen, and > eventually even green light emissions are prevented. > > This is why there is a color differential with altitude; at high > altitude oxygen red dominates, then oxygen green and nitrogen > blue/red, then finally nitrogen blue/red when collisions prevent > oxygen from emitting anything. Green is the most common of all > auroras. Behind it is pink, a mixture of light green and red, followed > by pure red, yellow (a mixture of red and green), and finally, pure > blue.