A solar storm forecast for Thursday is expected to give sky gazers in 17 American states a chance to glimpse the Northern Lights, the colorful sky shows that happens when solar wind hits the atmosphere.Northern Lights, also known as aurora borealis, are most often seen in Alaska, Canada and Scandinavia, but an 11-year solar cycle that's expected to peak in 2024 is making the lights visible in places farther to the south. Three months ago, the light displays were visible in Arizona, marking the third severe geomagnetic storm since the current solar cycle began in 2019.The Geophysical Institute at the University of Alaska at Fairbanks has forecast auroral activity on Thursday in Alaska, Oregon, Washington, Idaho, Montana, Wyoming, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan, New York, New Hampshire, Vermont, Indiana, Maine and Maryland.Auroral activity also has been forecast for Canada, including Vancouver.Light displays are expected to be visible overhead in Milwaukee, Minneapolis and Helena, Montana, and low on the horizon in Salem, Oregon.; Boise, Idaho; Cheyenne, Wyoming; Annapolis, Maryland; and Indianapolis, according to the institute.The National Oceanic and Atmospheric Administration's Space Weather Prediction Center said people wanting to experience an aurora should get away from city lights and that the best viewing times are between 10 p.m. and 2 a.m. local time.Northern Lights occur when a magnetic solar wind slams into the Earth's magnetic field and causes atoms in the upper atmosphere to glow. The lights appear suddenly and the intensity varies.A geomagnetic index known as Kp ranks auroral activity on a scale from zero to nine, with zero being not very active and nine being bright and active. The Geophysical Institute has forecast Kp 6 for Thursday's storm.

The Northern Lights have fascinated people for years, but no one could explain what caused them until now.

Physicists from the University of Iowa announced they've proven that the phenomena known as Alfven waves produce accelerated electrons toward Earth, which causes particles to create the lights.

The physicists said they used "specially designed instruments" to launch the Alfven waves down a 20-meter long chamber to measure the electrons that were accelerated by the electric field.

"These particular electrons undergo resonant acceleration by the wave's electric field, similar to a surfer catching a wave and being continually accelerated as the surfer moves along with the wave," the physicists said.

This idea of electrons "surfing" on the electric field was first introduced in 1946 by Russian physicist Lev Landau. It later became known as Landau damping, CNN reported.