Discover the cosmos! Each day a different image or photograph of
our fascinating universe is featured, along with a brief
explanation written by a professional astronomer. 2012 September
23 Explanation: Yesterday was an equinox, a date when day and
night are equal. Today, and every day until the next equinox,
the night will be longer than the day in Earth's northern
hemisphere, and the day will be longer than the night in Earth's
southern hemisphere. An equinox occurs midway between the two
solstices, when the days and nights are the least equal. The
picture is a composite of hourly images taken of the Sun above
Bursa, Turkey on key days from solstice to equinox to solstice.
The bottom Sun band was taken during the winter solstice in 2007
December, when the Sun could not rise very high in the sky nor
stay above the horizon very long. This lack of Sun caused
winter. The top Sun band was taken during the summer solstice in
2008 June, when the Sun rose highest in the sky and stayed above
the horizon for more tha