Why Aren't the Northern Lights Dangerous?

[Jim_B]

IANAScientist. But I think I understand some things fairly well. Like the earth’s magnetic field. It apparently protects us from the Sun’s radiation, which is a good thing. Life wouldn’t be possible on earth without it.

Anyway strange as it may sound, that is why I don’t understand travel to either one of the earth’s poles. People apparently do it all the time. But shouldn’t that be dangerous?

I mean all that radiation coalesces at the poles, doesn’t it? So shouldn’t people who go to the poles die almost immediately from radiation poisoning? Because isn’t that what the Aurora Borealis and the Aurora Australis represent? All that radiation collecting in one spot?

I trust you can see why I am confused.

:):):):):):)

[dtilque]

Auroras are caused by electrons and protons from the Solar Wind hitting atoms in the upper atmosphere. That ionizes those atoms and they glow when they recombine with free electrons. In the case of protons, they emit light when combining with free electrons to form hydrogen.

The thing is, it’s only visible light that reaches us down here on the surface. The electrons and protons, which are potentially dangerous, don’t penetrate all the way to the ground. And that visible glow is very weak, since obviously, the aurora is not very bright. So there’s no danger to surface inhabitants.

[Machine_Elf]

@Jim_B

I mean all that radiation coalesces at the poles, doesn’t it? So shouldn’t people who go to the poles die almost immediately from radiation poisoning?

They don’t die immediately, but they do get exposed, especially if they’re in airplanes.

https://www.nasa.gov/centers/langley/science/polar-radiation.html

@NASA

Since 1999, the number of flights over the North Pole from the U.S. has risen from around a handful of demo flights to more than 5,000 a year and growing.

While one or two flights will not exposure passengers and crew to lethal doses of radiation, multiple flights definitely pose an additional health risk, Mertens says.

“The average commercial airline pilot receives more radiation exposure than a fuel-cycle worker in a nuclear power plant,” he says.

Prediction will be especially critical during solar events that cause large spikes in the amount of radiation entering through the poles. The recommended annual limit can be exceeded in just one high-latitude flight.

[naita]

@Jim_B

I mean all that radiation coalesces at the poles, doesn’t it? So shouldn’t people who go to the poles die almost immediately from radiation poisoning? Because isn’t that what the Aurora Borealis and the Aurora Australis represent? All that radiation collecting in one spot?

I trust you can see why I am confused.

:):):):):):)

What do you mean by “all that radiation”? All the radiation the magnetosphere protects us against? If so, no. A lot of that radiation is deflected completely around the Earth. I don’t know how much, as the sources comprehensible to you and me don’t include such details, but have a look at this illustration for a rough idea of the concept:

Structure of the magnetosphere

[naita]

@Machine_Elf

They don’t die immediately, but they do get exposed, especially if they’re in airplanes.

https://www.nasa.gov/centers/langley/science/polar-radiation.html

And to add to that. If the magnetosphere vanished we wouldn’t immediately be wiped out either. It would mean increased cancer risk and other issues with long term radiation exposure though.

[scr4]

The atmosphere is our primary protection against radiation. The magnetosphere does help protect the atmosphere from being blown away by the solar wind.

[RioRico]

Ascending into an aurora probably isn’t too healthy without sufficient oxygen.

[Yakamaniac]

The term ‘radiation’ is awfully broad. Light is radiation. Heat is radiation. Radio/TV broadcasts are radiation. Charged particles from the Sun are dangerous to space travelers, especially if they are at the altitude where the Van Allen belts concentrate those charged particles. The atmosphere stops most of these particles, The poles bring the activity close to the Earth, but the radiation does not reach the ground. The International Space Station orbits near the altitude of the auroras, but does not go very close to the poles.

[Limmin]

There are dangerous places to remain in orbit thanks to the mechanism you described, Jim, and those are the “Van Allen Radiation belts.”

We are safe from such harmful radiation (auroras, Van Allen etc.) down here on earth thanks to two factors: Distance and the atmosphere.

To coin an analogy: Don’t fear the heat of a Pizza oven at an Italian restaurant.

Why? It’s hot and could burn you badly. You are safe because the walls of the oven and the kitchen block the heat (like the atmosphere) and the oven is also way on the other side of the restaurant from your seat (the 100+ km distance).