The Northern Lights (aurora borealis) are caused by charged particles from the Sun interacting with the Earth's atmosphere and magnetic field. When solar activity releases streams of charged particles, such as during solar flares or coronal Mass Ejections, these particles travel toward Earth along the solar wind. They are guided by the planet’s magnetic field toward high-latitude regions near the Arctic. As these energetic particles collide with gases in Earth's upper atmosphere (primarily oxygen and nitrogen), they transfer energy to the gas molecules. When the excited atoms return to their ground state, they emit light. The specific colors you see depend on the gas and the energy of the collisions: for example, green and pink lights commonly come from oxygen, while purples and blues can involve nitrogen. Key points about when and where the aurora occurs:

• They are most visible at high latitudes, around the polar regions, in the auroral ovals.
• They tend to peak around periods of high solar activity, such as solar maximum, when more charged particles reach Earth.
• They can appear as curtains, rays, or diffuse glows, and their shapes and colors vary with atmospheric conditions and the energy of incoming particles.

If you’d like, I can tailor this explanation to a specific region or provide tips on optimizing viewing conditions and timing for your location.