Today in Eurasia, North America and most of Africa, came the longest day of the year, and in Australia and South America is the shortest. This astronomical event is called a summer (or winter) solstice. Today in Moscow the sun rose at 3:45, and again disappear over the horizon only at 21:18 — so of daylight in the capital of Russia will last for over 17 hours and a half. North of the Arctic circle the sun does not come over the horizon.
photo: Elena Minashkina
The summer solstice occurs when the angle between the plane of equator to orbit its rotation around the Sun takes the smallest value. The inclination of the axis of rotation of the Earth plays a key role in the change of seasons on it, so the summer solstice is sometimes referred to as the beginning of “astronomical summer”.
Depending on the shift of the calendar, the summer solstice occurs on 20 or 21 June (on the 20th it falls in leap years). On the longest day of the year the sun rises at a maximum height above the horizon — today it was 57 degrees.
In many countries, the longest day of the year dedicated national holidays, although, as a rule, they are tied to a particular calendar date, and not necessarily to the day on which the solstice falls from the astronomical point of view. One example can be called folk festival of the Eastern Slavs Ivan Kupala, which is celebrated from the evening of 23 June (6 July new style) and 24 June (7 July). In some countries — in particular, in Sweden and in Latvia — solstice even officially a holiday.
Starting tomorrow a day in the Northern hemisphere will begin gradually to decline, and in South to increase. On September 22, will have the day of the vernal equinox, and on 21 December — the winter solstice.Related posts: