Colin Devroe

Reverse Engineer. Blogger.

The first day of Summer, I mean, Winter

June 20, 2008

Today is the first day of Summer here in North America.  The sun will shine longer today than any other day this year.  But one must not forget about the rest of the world.  Those on the other side of our planet are experiencing the direct opposite; the first day of Winter and the shortest day of the year.

So, by way of review here are the many names of the solstice.  This being copied directly from Wikipedia.

  • Summer solstice and winter solstice are the most common names. However, these can be ambiguous since seasons of the northern hemisphere and southern hemisphere are opposites, and the summer solstice of one hemisphere is the winter solstice of the other.
  • Northern solstice and southern solstice indicate the direction of the sun’s movement. The northern solstice is in June on Earth, when the sun is directly over the Tropic of Cancer in the Northern Hemisphere, and the southern solstice is in December, when the sun is directly over the Tropic of Capricorn in the Southern Hemisphere.
  • June solstice and December solstice are an alternative to the more common “summer” and “winter” terms, but without the ambiguity for which hemisphere they are intended. They are still not universal, however, as not all people on Earth use a solar-based calendar where the solstices occur every year in the same month (as they do not in the Hebrew calendar, for example), and the names are also not useful for other planets (Mars, for example), even though these planets do have seasons.
  • First point of Cancer and first point of Capricorn. One disadvantage of these names is that, due to the precession of the equinoxes, theastrological signs where these solstices are located no longer correspond with the actual constellations.
  • Taurus solstice and Sagittarius solstice are names that indicate in which constellations the two solstices are currently located. These terms are not widely used, though, and until December 1989 the first solstice was in Gemini, according to official IAU boundaries.
  • The Latin names Hibernal solstice (winter), and Aestival solstice (summer) are sometimes used.

Now you know.  If you live anywhere in the northern hemisphere get outside today and enjoy the first day of our summer.  If you live anywhere in the southern hemisphere find a good book and a cup of soup.