Solar wind is a stream of charged particles, mostly protons and electrons, that are continuously emitted by the sun. These particles are electrically charged and are accelerated by the sun's magnetic field.
When the solar wind reaches the Earth's magnetic field, it interacts with it, causing the magnetic field to distort and stretch out into a long tail on the night side of the Earth. This process is known as magnetic reconnection.
As the charged particles from the solar wind approach the Earth's atmosphere, they collide with the oxygen and nitrogen molecules in the atmosphere. These collisions can transfer energy to the molecules, exciting them to higher energy levels.
When the excited oxygen and nitrogen molecules return to their ground state, they release the excess energy in the form of light. This light creates the colorful auroras that we see in the polar regions of the Earth.
The color of the aurora depends on the energy of the particles and the type of molecule they interact with. Oxygen molecules emit a greenish-yellow light, while nitrogen molecules emit a red or blue light.
The script section defines two variables, particleCount and particleSpeed, which are used to set the initial number of particles and their speed. The script also defines functions to update the particle count and speed based on user input.
The script then creates an array of particles with random positions and velocities, and draws them on the canvas using the drawParticle function. The updateParticle function updates the particle positions based on their velocities. If a particle goes outside the canvas boundaries, it is removed from the array and a new particle is created in a random position with a random velocity.
Finally, the draw function clears the canvas and updates and draws each particle on the canvas. The requestAnimationFrame method is used to create a loop that continuously updates and draws the particles on the canvas.