What are Northern lights (aurora borealis)?

The northern lights are an atmospheric phenomenon that's regarded as the Holy Grail of skywatching.

The northern lights, or the aurora borealis, are beautiful dancing waves of light that have captivated people for millennia.

But for all its beauty, this spectacular light show is a rather violent event.

Energized particles from the sun slam into Earth's upper atmosphere at speeds of up to 45 million mph (72 million kph), but our planet's magnetic field protects us from the onslaught.

As Earth's magnetic field redirects the particles toward the poles — there are southern lights, too

Auroras occur on other planets, too — all that's required to make an aurora is an atmosphere and a magnetic field.

The best time of year to see the northern lights is between September and April, when the sky gets dark enough to see the aurora.