Close-up of the surface of a plasma globe, showing streams of glowing plasma connecting to its glass shell. A plasma globe is a glass sphere filled with noble gases (usually neon, krypton and xenon) at low pressure, with a very high voltage, high frequency electrode at its centre. The electrical energy ionises regions of the gas, which form a glowing plasma that extends to the insulating glass shell of the globe, where they form bright spots. The streams of plasma can be attracted to conducting objects placed on the outside of the globe, such as fingers.