How does aurora happen

The green bands of light in the sky are an aurora australis, an aurora at the south pole. They sure do! Auroras are not just something that happen on Earth. If a planet has an atmosphere and magnetic field, they probably have auroras.

We've seen amazing auroras on Jupiter and Saturn. These swirls of red light are an aurora on the south pole of Saturn. Want to make some aurora art? Check out this pastel aurora activity! What Is an Aurora? More about the sun! The sun sends us more than heat and light; it sends lots of other energy and small particles our way.

There is a constant streaming solar wind and there are also solar storms. During one kind of solar storm called a coronal mass ejection, the sun burps out a huge bubble of electrified gas that can travel through space at high speeds. There, the particles interact with gases in our atmosphere resulting in beautiful displays of light in the sky. Oxygen gives off green and red light.

Nitrogen glows blue and purple. They zoom along the field lines towards the ground to the north and south, until huge numbers of electrons are pushed down into the upper layer of the atmosphere, called the ionosphere.

In the ionosphere, the speeding electrons collide violently with gas atoms. This gives the gas atoms energy, which causes them to release both light and more electrons. In this way, the gases of the ionosphere glow and conduct flowing electric currents into and out of the polar region. The electrons flowing back out don't have as much energy as the speedy incoming ones had - that energy went into creating the aurora!

The Earth's "magnet" is deep in the core. Since we can't see the magnetic field, we draw lines to represent it. The field lines go into and out of the Earth around the Earth's magnetic poles. Where the lines are closest together the field is strongest. Where they are furthest apart it is weakest. Can you tell where the magnetic field is the strongest? Where is it weakest?

What Makes Auroras Happen? To Listen to this clip you will need the RealAudio player. Main Menu Self-Guide Menu. This wind is always pushing on the Earth's magnetic field, changing its shape.