The SAR and the Milky Way
Image Credit &
Copyright:
Julien Looten
This broad,
luminous red arc
was a surprising visitor to
partly cloudy evening skies over northern France.
Captured extending toward the zenith in a
west-to-east mosaic
of images from November 5,
the faint atmospheric ribbon of light is
an example of a Stable Auroral Red (SAR) arc.
The rare
night sky phenomenon
was also spotted at
unusually low latitudes around world,
along with more dynamic auroral displays
during an
intense geomagnetic storm.
SAR arcs and their relation to auroral emission have been
explored by citizen science
and
satellite investigations.
From altitudes substantially above the normal auroral glow,
the deep red SAR emission is thought to be caused by strong heating
due to currents flowing in
planet Earth's inner
magnetosphere.
Beyond this SAR, the Milky Way arcs above the cloud banks
along the horizon,
a regular visitor to night skies over northern France.