What Causes The Northern Lights? Scientists Finally Know For Sure

Nothing can ruin our joy in the aurora borealis, or Northern Lights, those ribbons of blue, green and violet light that cascade from the sky. Not even knowing for sure what causes them.

Physicists have long speculated about what gives rise to this very specific light phenomenon that occurs in the Earth's polar regions.

Now they're certain.

An published in this week suggests that the natural light show starts when disturbances on the sun pull on Earth's magnetic field. That creates cosmic undulations known as Alfvén waves that launch electrons at high speeds into Earth's atmosphere where they create the aurora.