CNN News:拉普兰上演炫目极光秀

The region known as Lapland includes a part of which of these nations? Greenland, Finland, Iceland or Scotland? Part of Russia, Norway, Sweden and Finland are located in Lapland.
And it's in Lapland that an extraordinarily light show was recently visible, courtesy of mother nature. The Aurora Borealis or Northern Lights twisted, danced and glowed in hues of green. Though the phenomenon can be seen at any time of the year, late winter or early spring during the overnight hours is said to be the best time to see them here. Besides being really "purrdy" to look at, there is some science behind these wondrous waves.

JENNIFER GRAY: Described as one of Earth's greatest light shows, an aurora is one of the most fascinating and beautiful naturally-occurring phenomena. You might know it as the Northern Lights, but its technically called the Aurora Borealis in the Northern Hemisphere and the Aurora Australia or Southern Lights in the Southern Hemisphere. This phenomenon occurs above the magnetic poles in the Northern and Southern Hemispheres.
They form when gases, particles in the Earth's atmosphere collide with charged particles released from the sun. Electrons and protons from the sun are blown toward the Earth by the solar wind.
As these are carried towards Earth, most of them are deflected by Earth's magnetic field. However, the magnetic field is weaker at the poles, allowing some of the particles to funnel into the Earth's atmosphere. The vibrant colors produced are determined by the type of gases that are colliding. The result is a brilliant display of the common green and yellow, less common blue and violet, even rare reds painting the night sky in ribbons, arcs or shooting rays.
Oxygen produces green and red light while nitrogen gives off blue and purple. The best time of year to view the light show is during the winter months when the nights are longer, under a cloud-free sky away from light pollution.