People are seeing aurora lights in both the north and south hemispheres this weekend. Is that normal? Why are these phenomena centered on the poles?

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I have family in the northern US posting pictures of the northern lights. My friends in Australia said their feeds are full of similar pictures. Is it normal for magnetic storms to cause effects in both hemispheres? Why are these effects centered off the poles? I’m not in the viewing circle. I’m jealous.

In: Planetary Science

3 Answers

Anonymous 0 Comments

The lights are from charged particles from space entering the Earth’s atmosphere and reacting to it. Of note, the green and red light is from interactions with high altitude oxygen at different altitudes. Nitrogen mostly produces the blue or violet colors, with some read. This process is actually the same idea as how neon lights work – which often do not actually use neon, depending on the desired color. Other colors are caused by these colors mixing, in the same way your computer monitor produces all colors from just red, green, and blue light.

Due to this cause, the center is at the magnetic poles. These poles also tend to act as funnels and a high amount of the charged particles that collide with the magnetic field enter the atmosphere at the poles. Over time, the poles move around, but generally stay pretty close to the geographic poles that the Earth spins around.

Due to the magnetic nature, both the northern and southern lights will be of about equal strength with the angle and distance to the Sun meaning the side closest to winter will have a very slightly stronger display. However, the landmasses and population of the Earth are heavily centered in the northern hemisphere, meaning the southern lights are generally much less visible to people, and much less talked about.

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