Since I am currently in the Northern Hemisphere, December 22 marks the
winter solstice. The winter solstice is the time of the longest night and
shortest day of the year, because the sun will be at its lowest point in the
sky. In the Southern Hemisphere it is now the summer solstice. For the summer
solstice it is the longest day and shortest night of the year.
Solstice is from the Latin word, solstitium, meaning ‘sun standing still.’
The sun seems to stand still at the Tropic of Capricorn and then reverses its
direction as it reaches the southernmost position, as seen from Earth. Some
people call it ‘sunturn.’ The sun will seemingly stand still for three days (it will rise from the same point each day).
While June 21 is the summer solstice in the Northern Hemisphere, the winter
solstice does not always fall on December 21 (six months later). It can be on
the dates 20-23 (but generally on 21 or 22 December). For example, winter
solstice on December 23 is rare – the last time was in 1903, and the next time
will be in 2303.
Solstice is measured by the solar noon – the time midway between sunrise
and sunset, which is when the sun is at its highest point in the day. The exact
time of solar noon is measured by the Earth’s rotation. The December solstice
is measured from one solar noon to the next – which is 30 seconds longer than
24 hours. So two weeks before the solstice the sun reaches solar noon at
11:52am and on the winter solstice the sun is at solar noon at 11:59am. This
means that there are earlier sunsets before the winter solstice and
increasingly later sunrises for a few weeks after the winter solstice. In the
Northern Hemisphere the earliest sunset occurs in early December and the latest
sunrise occurs in early January.
Happy solstice!
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