Explanation:
September's equinox
arrives tomorrow as the Sun crosses the celestial equator heading south.
The event marks the astronomical beginning of spring
in the southern hemisphere and autumn in the north.
And though
the connection
is still puzzling, the equinox seasons bring an increase
in geomagnetic storms.
So as northern nights grow longer, the equinox also heralds
the arrival of a good season for
aurora hunters.
Recorded on September 20,
these colorful northern lights
were captured with camera and wide-angle lens
near the Norwegian Sea coast outside Tromsø in Northern Norway.
Shining at
altitudes of 100 kilometers or so,
the aurora rays are parallel, but perspective makes them appear to
radiate from a vanishing point behind the silhouetted pine tree.
Stars in this enchanting northern night
include Polaris
above and right of the tree top, and
yellowish giant stars
Shedar
(Alpha Cassiopiae) to the left and
Kochab
(Beta Ursae Minoris) to the right.
Bright Altair shines
through the greenish auroral curtain at the lower left of the scene.
