Auroras are light displays that can sometimes
be seen in the night sky, especially at extreme northern and southern
latitudes. Auroras are caused by energetic particles from the magnetosphere.
Coronal mass ejections can bring about intense auroral displays.
Ordinarily, the magnetosphere deflects most of
the particles of the solar wind. However, some solar wind particles
do manage to leak in. These enter the earth’s atmosphere
along the magnetic field lines; that is, at the North and South
When these particles (mainly electrons) collide
with gas molecules (mainly oxygen and nitrogen) in the upper atmosphere,
they excite the gas particles to higher energy states. As these
gas molecules “de-excite” back
down to lower energy levels, they release light. This light produces
the often gorgeous auroras, which can be green, red, or purple,
and appear as curtains, arcs, or clouds.
Since charged particles enter our atmosphere at the poles, auroras
are most often seen at extreme latitudes. A common latitude for
sightings is 67°, or roughly the latitude of Fairbanks, Alaska.
During geomagnetic storms, however, auroras may be visible at much
The likelihood of auroral displays can be predicted
by tracking incoming particles. Particles entering the upper atmosphere
are measured by a satellite orbiting the earth’s poles—the
Polar-orbiting Operational Environmental Satellite, or POES. Data
from this satellite are compared to statistical data of auroral
sightings to produce the maps predicting where auroras are currently
Look for current auroras using live