Types of Auroras
Shapes
Auroras come in many different forms. Here are some:
These different shapes are caused by 4 different reasons.
1. The Changing Input of the Sun
Depending on the amount of particles that shoot from the sun, the magnetic field will react differently, causing the amount of particles to enter Earth to vary.
2. Earth's Upper Atmosphere
The magnetic field is always changing, especially with pollution. Since the magnetic field is such a vital part of this process when there is a slight change to the magnetic field, it can change the shapes drastically. Additionally, the wind can move these particles.
3. The Motion on the Planet
Scientists are still trying to study why this is the case, but there has been shown a clear correlation between the two. Also, when the Earth moves farther away from the sun the impact of these particles may change slightly. However, this won't happen for a very long period of time.
4. Particles on Earth
All the particles on the Earth interact differently with the charged particles. The light produced may also be different. So, there are many times when there might be a reaction but a person's eyes are not able to see it. So, this could vary the shapes slightly.
Colours
Auroras come in many colours including blue, green, red, and orange. These colours are caused by the interaction of solar particles and the Earth's atmosphere.
Earth's atmosphere is 99% nitrogen and oxygen. From Science 10 we have learned that when an atom absorbs energy it creates photons. Well, this is the process of making auroras. Atoms are put into an excited state, and release photons, this process is called electromagnetic radiation. Depending on the particle it will release different lights. Green is a common colour. It is created when charged particles strike with oxygen at an altitude of 100 to 300 km. Pink or dark red is a less common type of auroras. It is produced by nitrogen molecules at an altitude of around 100 km. Red is found in the higher atmosphere, and it is created from oxygen atoms. Blue and purple is from hydrogen and helium. However, it can be difficult for us to see.