Northern Lights light up the Bay Area night sky

A geomagnetic storm Tuesday night caused the Aurora Borealis to be visible across much of the northern United States and as far south as Northern California.

How northern lights happen

The sun is at the maximum phase of its 11-year activity cycle , making the light displays more common and widespread. Colorful northern lights have decorated night skies in unexpected places and space weather experts say there are more auroras still to come.

Aurora displays known as the northern and southern lights are commonly visible near the poles, where charged particles from the sun interact with Earth’s atmosphere.

Skygazers are spotting the lights deeper into the United States and Europe because the sun is going through a major face-lift. Every 11 years, its poles swap places, causing magnetic