solsticii

Solsticii refers to the astronomical events that occur twice each year when the Sun reaches its highest or lowest point in the sky at noon. These are the times when the Sun appears to stand still in its declination before reversing its direction. The word "solstice" comes from the Latin words "sol" meaning sun and "sistere" meaning to stand still.

There are two solstices: the summer solstice and the winter solstice. The summer solstice occurs around June 20th or 21st in the Northern Hemisphere and around December 21st or 22nd in the Southern Hemisphere. On this day, the hemisphere tilted towards the Sun experiences its longest day and shortest night. Conversely, the winter solstice occurs around December 21st or 22nd in the Northern Hemisphere and around June 20th or 21st in the Southern Hemisphere. This marks the shortest day and longest night of the year for that hemisphere as it is tilted furthest from the Sun.

The tilt of the Earth's axis, approximately 23.5 degrees, is the reason for the solstices and the changing seasons. During the summer solstice, the Earth's axis is tilted most directly towards the Sun, leading to more hours of daylight. During the winter solstice, the axis is tilted most directly away from the Sun, resulting in fewer hours of daylight. These events have been observed and celebrated by various cultures throughout history, often marking agricultural cycles and important festivals. The precise timing of the solstices varies slightly each year due to the Earth's orbit not being a perfect ellipse and the leap year system.