This entry is about auroras! The inspiration behind this is https://spacedashboard.com/, which has a aurora forecast panel on it. I think the aurora has something to do with the ionosphere, the sun, and the earth’s magnetic field.

Let’s go to a basic explanation:

The suns sends solar wind, small electrified particles. Earth’s magnetic field traps these electrified particles. Sometimes the sun lets out a massive “burp,” or solar storms. During a particular type of storm, called a coronal mass ejection, the sun lets out a bigger “burp” which sends particles zooming through space. Some of the particles dive into earth’s atmosphere near the southern and northern hemisphere. They bump into gases in our atmosphere, and these interactions cause the aurora.

Wait wait wait wait…. it’s not this simple is it?

Let’s start with neon signs, because…. you’ll see. When you put a high voltage across a gas, it causes the electrons in the gas to fly off. When the electrons come back together with the gas, a little bit of light is emitted. When mass is ejected from a coronal mass ejection, all this plasma is released. This plasma bumps off electrons from gas in the atmosphere. When the electrons come back the the atoms, light is released.

It’s similar to how when electrons get excited and then go back to the there original state, they release photons (particles of light):

What about different colors of aurora? Well, if you change the gas or layer of the atmosphere (with different distributions of gases), the color changes. Oxygen emits green and red light. Nitrogen emits blue and purple.

Do auroras happen on different planets? Yes! If the sun affects the planet, if it has an atmosphere, and if it has a magnetic field, auroras can occur. We’ve seen auroras on Jupiter and Saturn.

We can even forecast auroras! The space weather prediction center uses the OVIATION (Oval Variation, Assessment, Tracking, Intensity and Online Nowcasting) model. The model uses the solar wind velocity and interplanetary magnetic field measured at 1.6 million km form earth as input. As output, it calculates three types of electron precipitation (when trapped electrons enter earth’s atmosphere) and proton precipitation, both of which strongly correlate with the aurora. When electrons from electron precipitation enter the atmosphere, they collide with atoms and knock off the atom’s electrons. When those electrons recombine with their gases, they emit light.