Auroras occur on Earth when ionized particles from
the sun interact with air molecules in the upper atmosphere.
The particles are deflected toward the North and South
Poles by Earth's magnetic field, so auroras are most
often visible at very high latitudes. When the ionized
particles enter Earth's upper atmosphere (the ionosphere),
their reaction with gas molecules can look like colorful
light particles raining down. The ground-based images
of auroras were taken in Alaska.
! Click each image to see a larger