To make it possible to reproduce the aurora phenomenon in the upper atmospheric layer by placing a particle generating section and a magnet in a vacuum device on the ground.

The simulated earth consisting of the particle generating section and the magnet is set in a vacuum vessel. Particles are jumped out of metal and an accelerated by an electric field in the particle generating section. The magnet is made conductive on its circumfrtrnce so that the electric field is impressed between the magnet and the particle generating section. The vacuum vessel is used and many needle-like electrodes are laced in the upper part of the vessel. Aurora particles are generated by the electric field release by the high voltage impressed on these electrodes. The pressure in the vessel is set near the atm. pressure in the upper atmosphere of the earth. Electric discharge is generated by the electric field impressed between the needle-like electrodes and a conductor formed simulating the earth. Light emission having the same line spectrum as that of the aurora is thereby reproduce. The fact that the forms of the light emission around the earth are entirely different is indicated by converting the polarity of the particle generating section to positive and negative polarities. The light emission occurs in a disk shape on the equatorial sky so as to surround the earth if the electrodes of the generating section are set positive. The light emission has the form along both south and north magnetic poles and is visible like curtains from the ground if the electrodes are set negative.