Question

why aurora occurs only at poles

Answer 1

The aurora can be seen most strongly at the poles of the Earth. In the north, it is called Aurora Borealis and in the south, it is called Aurora Australias. Of the two poles, the aurora can be seen the strongest near the arctic circle in the Northern Hemisphere. The reason that the Aurora can only be seen at the poles has to do with how the Earth's magnetic field acts. The Earth has a metal core and acts much like a bar magnet with two poles and a magnetic field. Those charged particles get sucked into the Earth's magnetic field and are then channelled toward the poles, where they are channelled toward a ring around each pole. The charged particles are trapped in the loops of the magnetic field and are then carried toward the poles, where the particles hit the atmosphere and create the aurora that we see.