Explanation:
September's equinox
arrives today at 0905 UT.
As the Sun crosses the celestial equator heading south, spring
begins in the southern hemisphere and autumn in the north.
And though
the seasonal connection
is still puzzling,
both spring and autumn bring an increase in geomagnetic storms.
So as northern nights grow longer, the equinox also heralds
the arrival of a good season for
viewing aurora.
Recorded earlier this month,
these curtains
of September's shimmering green light
sprawl across a gorgeous night skyscape.
In the foreground lies Hidden Lake Territorial Park
near Yellowknife, Northwest Territories, Canada.
Calm water reflects the aurora, with bright star trails peering
through the mesmerizing sky glow.
Of course, shining at altitudes of 100 kilometers or so,
planet Earth's auroras are
visible from space.
