An equinox occurs twice a year (around 20 March and 22 September), when the tilt
of the Earth
's axis is inclined neither away from nor towards the Sun
, the center of the Sun being in the same plane as the Earth's equator
. The term equinox can also be used in a broader sense, meaning the date when such a passage happens. The name "equinox" is derived from the Latinaequus (equal) and nox (night), because around the equinox, the night and day have approximately equal length.
The date at which sunset and sunrise become exactly 12 hours apart is known as the equilux. Because times of sunset and sunrise vary with an observer's geographic location (longitude and latitude), the equilux likewise depends on location and does not exist for locations sufficiently close to the Equator. The equinox, however, is a precise moment in time which is common to all observers on Earth.
|
Sun compass: to the left of the picture,
the northern hemisphere, to the right - the
southern hemisphere |
|
You are right between two hemispheres |
Macapá is the only Brazilian capital crossed by the equator line. That’s why the inhabitants of the city have the privilege – at least twice a year – to watch the Equinox, when the sun rises, moves and sets exactly along the equator line. In this period days and nights on our whole planet are of equal length. And this phenomenon happens only twice a year : in March, known as “Spring Equinox” – and in September, the “Autumn Equinox”.
In Macapá the “Equinox” can be observed from the monument “Marco Zero”. Apart from locals, the phenomenon attracts tourists and scientists. This year it was set for Sep. 22nd at 11:49. Local of observation : City of Macapá.
Source: Wikipedia
No comments:
Post a Comment