One of the most beautiful examples of naturally occuring plasma is the Aurora Borealis, or Northern Lights. The interaction between the sun’s solar winds and the earth’s atmosphere creates the famous light show at the north and south pole (Aurora Australis). The earth’s magnetic field plays a crucial role in directing the plasma towards the poles.
We’ve constructed a northern lights demo based on the drawings of Dr. Jean Lilensten from the Institut de Planétologie et d'Astrophysique de Grenoble in France. The Planeterrella consists of a glass bell jar holding an aluminum sphere representing the earth and another sphere or a copper electrode representing the sun or other object in our solar system. By supplying a voltage between the “sun” and “earth”, we create a DC discharge in the chamber. A permanent magnet inside the earth sphere simulates the earth’s magnetic field and leads to interesting plasma phenomena, including the formation of a plasma ring around the pole similar to the northern lights. All of the non-metal components of the Planeterrella are created in our 3D printer laboratory.