1. Roman goddess of the dawn. The Greek
equivalent is Eos.

2. Coloured light in the night sky,
called aurora borealis, `northern lights', in
the northern hemisphere and aurora australis
in the southern hemisphere. An auroras is
usually in the form of a luminous arch with
its apex towards the magnetic pole followed
by arcs, bands, rays, curtains, and coronas,
usually green, but often showing shades of
blue and red, and sometimes yellow or white. 
Auroras are caused at a height of 100 km/60
mi by a fast stream of charged particles,
originating in the Sun.  These enter the
upper atmosphere and, by bombarding the gases
in the atmosphere, cause them to emit visible
light.
The magnetic field of the Earth divides the
concentration into its north and south zones.
The French philosopher Gassendi coined the
term `northern dawn` 1621.

Subject by: Russell Webb