Museo Galileo
italiano
Virtual Museum
In-depth
Aurora borealis
Aurora borealis

Spectacular luminescence observed mainly near the poles at altitudes between 100 and 500 km. Produced by the charged particles from the Sun carried by the solar wind that are diverted from the terrestrial magnetic field and collide with gas molecules in the atmosphere. These shocks excite the molecules, which, reverting to their original state, emit light.