On Thursday there will be a moment of spring equinox. This is the day when the beginning of astronomical spring falls. Interestingly, contrary to appearances, during the equinox day and night are not perfectly the same length. And when does a calendar spring start?
The beginning of astronomical spring is associated with the moment of equinox. In the northern hemisphere it falls at the time of the sun through the so -called A ram point. It is a conventional place of intersection of the ecliptic and the blue equator. The ecliptic is a circle, after which the sun seemingly moves in the sky during the year. In turn, the blue equator can be imagined as an extension in cosmos Earth's equator plane. The second place of intersection of these districts is the weight point. Its exceeding by the sun means the beginning of autumn in the northern hemisphere.
Spring equinox 2025. When astronomical spring begins
In 2025, the moment of the spring equinox will fall on Thursday, March 20, when in Poland it will be 10.01. Interestingly, the name “equinox” is not entirely true. It is associated with the definition of sunrise and sunset – we define them as the moment when the upper edge of the sun shield affects the sufficiently eastern or western horizon.
The geometric agent of the sunny disc is used to determine the equinox. The time needed for the sun for a full sunset, which can be a few minutes, makes the day a little longer than the night. In addition, the atmosphere curves sunlight, which makes the sun sometimes seem higher in the sky in moderate latitudes than it really is.
On March 21, we will welcome a calendar spring, which will last until June 21.
When spring beginsIMGW-PIB
Time and Date, PAP, tvnmeteo.pl
Source of the main photo: PAP/EPA/Ronald Wittek