- Aurora
- To the Inuit of Hudson Bay, the aurora borealis or northern lights were
celestial torches that safely guided the dead to the heavenly regions. In
medieval Europe, the northern lights were thought by some to be the
reflections of heavenly warriors. To the modern scientist, the aurora
borealis or aurora polaris of the Arctic and the aurora australis of the
Antarctic are less of a mystery. Appearing as luminous -- and sometimes
colored -- arcs, rays and bands in the night sky in the high latitudes such
as this picture taken from a satellite, luminous auroras occur when the
constituents of the upper atmosphere are excited by charged particles from
space. While we can see auroras in visible light, auroras also occur in
the invisible infrared and ultraviolet regions of the electromagnetic
spectrum. The photo was obtained from an informational website about the Aurora Borealis of the Tromsø Museum of Norway. Image courtesy of CERN.