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21st June, 2011, - which happens to be the longest day of the year, marks the beginning of summer season for various countries in the northern hemisphere - including the United States of America. That being said, the same day will be the shortest day of the year and will mark the beginning of winter season for various countries in the southern hemisphere - including Australia and New Zealand. To cut it short, the northern and southern hemispheres experience 'summer solstice' at different times of the year. Now that is bound to be a bit confusing, unless you are well versed with some of the basic facts about the summer solstice - like how it occurs, when it occurs, etc.
Summer Solstice Information
In astronomy, the term 'solstice' refers to an astronomical event which occurs when the apparent position of the Sun is at its northernmost or southernmost limit in the sky. The tilt of the Earth at 23.5°, its rotation and its revolution are driving factors when it comes to a solstice. In the course of its journey, the Sun reaches the Tropic of Cancer (which happens to be its northernmost limit) in the month of June and the Tropic of Capricorn (which happens to be its southernmost limit) in the month of December. The Sun reaches the Tropic of Cancer - which results in a summer solstice in the northern hemisphere, mostly on the 20th or 21st of June and - in rare cases, on 19th or 22nd of June. This difference in dates can be attributed to the fact that we refer to the Gregorian calendar which has 365 days in a normal year and 366 in a leap year. More importantly, a study carried out at the Swinburne University of Technology also revealed that the orbital and daily rotational motion of the Earth also has a role to play in this change of summer solstice date.
In other words, the journey of the Sun can be traced from the Equator to the Tropic of Cancer, back to the Equator, then to the Tropic of Capricorn and once again to the Equator. (When the Sun is at the Equator, it is referred to as the 'equinox'. Like a solstice, even an equinox occurs twice a year - once in March and again in September.) This journey of the solar entity continues year after year, and is also responsible for the occurrence of seasons on the planet. When the Sun is at its northernmost extreme, it is referred to as the June solstice and when it is at its southernmost extreme in December it is referred to as the December solstice.
Summer Solstice or Winter Solstice?
Even though the solstice occurring in the month of June is quite popularly known as the summer solstice, the use of this term for this day i.e. June solstice is only restricted to the northern hemisphere. (The popularity of this term can be attributed to the fact that most of the countries of the world lie in the northern hemisphere.) In the southern hemisphere it is referred to as the winter solstice as it marks the beginning of winter for countries in this hemisphere. Simply put, the June solstice, which happens to be the summer solstice for people living in the northern hemisphere, is the winter solstice for people living in the southern hemisphere. Likewise, the summer solstice for the southern hemisphere occurs in December (22nd December, 2011,) which happens to be the winter solstice for the northern hemisphere.
Interesting Facts about the Summer Solstice
Going by the technically correct definition of a solstice, it is possible to determine the exact time of the event - correct up to the minute. On 21st June, 2011, the solstice will occur at 17:16 UTC. In colloquial sense though, the term is used to refer to the day on which the solstice (i.e. the astronomical event) occurs. For instance 21st June, 2011, 20th June, 2012, 21st June, 2013, etc. Given below are more of such summer solstice facts which are bound to leave you amazed.
The term 'solstice' is derived from the combination of Latin words 'sol' meaning 'the Sun' and 'stitium' meaning to 'stand still'.
While the people living in the northern hemisphere celebrate summer solstice in June, people in the southern hemisphere celebrate it in the month of December.
Irrespective of whether it is the northern hemisphere or the southern hemisphere, the summer solstice marks the longest day and shortest night of the year.
While the day of the summer solstice is considered to be the longest day of the year, the subsequent days will become shorter until we reach winter solstice in December - which will be the shortest day of the year.
While summer solstice is known to mark the beginning of summer in most of the cultures, in some cultures it is considered to mark mid-summer.
Towards the north of the Arctic Circle, the Sun remains above the horizon for the entire period of 24 hours; this phenomenon is referred to as the 'midnight-sun' and the region which experiences it is referred to as the 'Land of Midnight Sun'.
These regions which experience the midnight-sun include northern Alaska, northernmost regions of Canada,buy airmax, Norway, Sweden and Finland, and much of Greenland.
So 21st June, 2011, will mark the first day of summer 2011 in the northern hemisphere - the longest day of the year. The relevancy of summer solstice - or June solstice to be precise, is not just restricted to the field of astronomy, but goes well beyond that into mythology and folklore. Summer solstice celebrations differ from one part of the world to another, with various cultures celebrating the day in a peculiar manner. Some light bonfires to welcome the Sun, while some light bonfires to keep ghosts and ghouls out of the town. Some worship the god of light, and some celebrate it as the wedding of Heaven and Earth. Summer Solstice celebrations at Stonehenge are perhaps the most heard of, with thousands of individuals assembling at the site to welcome the Sun.