Stonehenge

Stonehenge is a prehistoric monument in Wiltshire, England, 2 miles (3 km) west of Amesbury and 8 miles (13 km) north of Salisbury. Stonehenge's ring of standing stones are set within earthworks in the middle of the most dense complex of Neolithic and Bronze Age monuments in England, including several hundred burial mounds.

Archaeologists believe it was constructed from 3000 BC to 2000 BC. The surrounding circular earth bank and ditch, which constitute the earliest phase of the monument, have been dated to about 3100 BC. Radiocarbon dating suggests that the first bluestones were raised between 2400 and 2200 BC, although they may have been at the site as early as 3000 BC.

The site and its surroundings were added to UNESCO's list of World Heritage Sites in 1986 and it is a legally protected Scheduled Ancient Monument. Stonehenge is owned by the Crown and managed by English Heritage; the surrounding land is owned by the National Trust.

Stonehenge could have been a burial ground from its earliest beginnings. Deposits containing human bone date from as early as 3000 BC, when the ditch and bank were first dug, and continued for at least another five hundred years.

Winter solstice

Winter solstice is an astronomical phenomenon marking the shortest day and the longest night of the year. In the Northern Hemisphere this is the December solstice and in the Southern Hemisphere this is the June solstice.

The axial tilt of Earth and gyroscopic effects of its daily rotation mean that the two opposite points in the sky to which the Earth's axis of rotation points (axial precession) change very slowly (making a complete circle approximately every 26,000 years). As the Earth follows its orbit around the Sun, the polar hemisphere that faced away from the Sun, experiencing winter, will, in half a year, face towards the Sun and experience summer. This is because the two hemispheres face opposite directions along Earth's axis, and so as one polar hemisphere experiences winter, the other experiences summer.

More evident from high latitudes, a hemisphere's winter solstice occurs on the shortest day and longest night of the year, when the sun's daily maximum elevation in the sky is at its lowest. The winter solstice itself lasts only a moment in time, so other terms are used for the day on which it occurs, such as "midwinter", or the "shortest day". It is often considered the "extreme of winter" (Dongzhi in the Chinese calendar). In meteorology, winter in the Northern Hemisphere spans the entire period of December through February. The seasonal significance of the winter solstice is in the reversal of the gradual lengthening of nights and shortening of days. The earliest sunset and latest sunrise dates differ from winter solstice, however, and these depend on latitude, due to the variation in the solar day throughout the year caused by the Earth's elliptical orbit (see earliest and latest sunrise and sunset).

National Geographic

National Geographic or NatGeo may refer to:

See also

English Heritage

English Heritage (officially the English Heritage Trust) is a registered charity that looks after the National Heritage Collection. This comprises over 400 of England's historic buildings, monuments and sites spanning more than 5,000 years of history. Within its portfolio are Stonehenge, Dover Castle, Tintagel Castle and the best preserved parts of Hadrian's Wall. English Heritage also manages the London Blue Plaques scheme, which links influential historical figures to particular buildings.

When originally formed in 1983, English Heritage was the operating name of an executive non-departmental public body of the British Government, officially titled the Historic Buildings and Monuments Commission for England, that ran the national system of heritage protection and managed a range of historic properties. It was created to combine the roles of existing bodies that had emerged from a long period of state involvement in heritage protection. In 1999 the organisation merged with the Royal Commission on the Historical Monuments of England and the National Monuments Record, bringing together resources for the identification and survey of England's historic environment.

Summer solstice

The summer solstice occurs when the tilt of a planet's semi-axis, in either northern or southern hemispheres, is most inclined toward the star that it orbits. Earth's maximum axial tilt toward the Sun is 23° 26'. This happens twice each year (once in each hemisphere), at which times the Sun reaches its highest position in the sky as seen from the north or the south pole.

The summer solstice occurs during a hemisphere's summer. This is the northern solstice in the northern hemisphere and the southern solstice in the southern hemisphere. Depending on the shift of the calendar, the summer solstice occurs some time between June 20 and June 22 in the northern hemisphere and between December 20 and December 23 each year in the southern hemisphere. The same dates in the opposite hemisphere are referred to as the winter solstice.

When on a geographic pole, the Sun reaches its greatest height, the moment of solstice, it can be noon only along that longitude which at that moment lies in the direction of the Sun from the pole. For other longitudes, it is not noon. Noon has either passed or has yet to come. Hence the notion of a solstice day is useful. The term is colloquially used like midsummer to refer to the day on which solstice occurs. The summer solstice day has the longest period of daylight – except in the polar regions, where daylight is continuous, from a few days to six months around the summer solstice.