The aurora borealis is a naturally-occurring colored light display that appears in the sky of the northern latitudes of the planetEarth. The effect is produced by the collision of charged particles, mostly electrons but also protons and heavier particles, from the magnetosphere, with atoms and molecules of the Earth's upper atmosphere.
Earth's aurora borealis is referred to in several scripts. The script of TOS: "Where No Man Has Gone Before" draws a parallel between the aurora borealis and the galactic barrier, describing the latter as "a display of energy similar to Earth's Aurora Borealis, a flaring curtain of energy." Similarly, the screenplay of Star Trek: The Motion Picture describes the V'Ger cloud, when seen from a distance at the start of the film, as vaguely resembling "an Aurora Borealis: flaring colors from the fringes, beautiful yet ominous."  In the final scene of the script for DS9: "Chimera", Odo is said to transform into "a gossamer cloud of plasma-like energy, an aurora borealis of golden color and light."