Aurora physics

Neon lights are glass tubes containing neon or other gases. When an electric current is sent from one end to the other, the current electrons collide with the neon electrons, raising them to a higher energy level. When those electrons relax and return to their ground state, they emit light. The color depends on the specific change in energy, meaning that different gases such as argon, xenon or mercury produce different colors.

For the Northern Lights, it’s not neon, but gases in the atmosphere. Oxygen gives green light at low altitudes and red light at high altitudes. Nitrogen produces blue or violet light. The yellow and pink colors are caused by a mixture of gases and usually only occur in the most intense solar storms. These gases are excited by a combination of the Sun’s energetic charges and the Earth’s own oscillating magnetic field, which gives these particles extra boost and creates more energetic collisions.

Wait, so the Earth’s magnetic field is changing now? Yes, and it’s caused by the solar wind itself. As moving charges experience a force in a magnetic field, they create their own magnetic field. When a flood of charged particles rains down on us, the Earth’s field bends and deflects. This causes it to spin around, leading to those spectacular light shows in the sky.

Another interesting fact: the aurora exists during the day, you just can’t see it.

What don’t you like?

Unfortunately, space weather isn’t just pretty lights. For any human in space, such as the International Space Station, or even in high-altitude aircraft, these fast-moving charged particles are a blast of unwanted radiation. In this case, it will be mostly beta radiation, but some alpha particles may also be obtained. (Here’s your radiation refresher.)

It is also difficult in satellites. Accumulation of charge can damage the electrical components needed for the satellite to function (whatever is possible). Also, by absorbing more of the Earth’s solar energy, the atmosphere heats up and causes its expansion. This increases the drag on spacecraft in low Earth orbit and slows them down. Bottom line: satellites can go off course or fall out of the sky.