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Earth's Hemispheres
The earth is traditionally described in relation to its two halves or
hemispheres, North and South of the Equator, an imaginary line circling the
earth midway between its two poles.
Northern Hemisphere
The Northern Hemisphere is the half of a planet's surface (or celestial
sphere) that is north of the equator. On Earth, the Northern Hemisphere
contains most of the land and population.
In the temperate regions of the hemisphere, winter lasts from around December
to February and Summer from around June to August. The earth's perihelion,
during which its orbital motion is fastest, occurs in January, and therefore
northern hemisphere winters tend to be shorter and less severe than southern
hemisphere winters at equivalent latitudes. Tropical regions tend to
experience a rainy season during the 'summer' months, and a dry season during
the 'winter' months.
Regions north of the Arctic circle will experience some days in summer on
which the sun never sets, and some days in winter on which the sun never
rises. The duration of these phases varies from one day for places right on
the Arctic circle to several months near the North Pole itself.
In temperate and polar regions of the Northern Hemisphere most of the year,
the sun passes from east to west in the south, causing sun-cast shadows to
turn clockwise through the day. In the tropics, the sun is always virtually
overhead, but will sometimes be in the south and sometimes in the north.
Southern Hemisphere
The Southern Hemisphere is the part of Earth's surface that is south of
the equator.
It contains four continents (Africa, Australia, most of South America and
Antarctica) and four oceans (South Atlantic, Indian, Pacific and Antarctic).
Summer occurs from December to February and winter from June to August.
This region has historically been seen as less developed and poorer than the
Northern Hemisphere. However, the Southern Hemisphere is also significantly
less polluted than the Northern Hemisphere due to lower overall population
densities, lower levels of industrialization, and smaller land masses across
the southern temperate zone.
In the Southern Hemisphere the sun passes from East to West in the North.
This generally causes sun-cast shadows to turn anticlockwise through the day.
The South Pole is oriented towards the galactic centre, and this, combined
with clearer skies makes for excellent viewing of the night sky from the
Southern Hemisphere.
This article is licensed under the GNU Free Documentation License. It uses material from
Wikipedia
and from ShiningRise.com
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