Mystery of Why Northern Lights "Dance" May Be Solved [News]
People have long marveled at the majestic and mysterious northern lights that light up the skies over the polar regions of countries like Canada and in Scandinavia. Scientists have known for years that these undulating auroras are caused by a storm of charged particles high above Earth. And although a sight to behold, the forces triggering these lights can endanger satellites and air travelers near the poles. But researchers were in the dark about just what forces acted on these so-called magnetic substorms to produce the shimmering lightshows that dazzle us--until now.Scientists have debated for decades whether local electrical disruptions in Earth's magnetic field or far-flung happenings in the so-called magnetotail (the tapering region of the magnetic field that points away from the sun) lead to the flare-ups of these substorms and their associated auroras. [More]