Auroras occur in the upper atmosphere, specifically in a region called the thermosphere, which extends from about 80 to 600 kilometers above Earth's surface.

They are most commonly seen in the high-latitude regions, near the Earth's magnetic poles. This is because the aurora is caused by charged particles from the sun (solar wind) interacting with the Earth's magnetic field, and these interactions are strongest at the poles.

Here's a breakdown:

* Northern Lights (Aurora Borealis): Occur in the Northern Hemisphere, primarily over Canada, Alaska, Greenland, Iceland, Norway, Sweden, and Finland.

* Southern Lights (Aurora Australis): Occur in the Southern Hemisphere, primarily over Antarctica, Australia, New Zealand, and parts of South America.

While the aurora is most visible at the poles, it can occasionally be seen at lower latitudes during periods of high solar activity.