New land is formed when rivers enter the ocean
The center of the Earth is made up of two layers, the outer core and the inner core. The outer core is the third layer of the Earth. It is the only liquid layer, and is mainly made up of the metals iron and nickel, as well as small amounts of other substances. The outer core is responsible for Earth's magnetic field.
Two questions which arises in my mind about aurora borealis are:
- Why does aurora borealis occur?
- Why does aurora borealis occur in a particular time of the year?
Answers:
- As solar wind approaches the Earth, it meets the Earth's magnetic field. In the ionosphere, the ions of the solar wind collide with atoms of oxygen and nitrogen from the Earth's atmosphere. The energy released during these collisions causes aurora borealis.
- Aurora borealis is active the whole year. Since it needs to be dark in order to see aurora borealis in the sky, late August/September through the very beginning of April is the best time to go to a destination located in the aurora zone for a chance to see them.
Note: These are the questions which arises in my mind only. It may differ from person to person.
Hope you could understand.
If you have any query, feel free to ask.