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Our
Earth is the most amazing planet that we know
of. It has green life, people, a harmonious
ecosystem and a complete life of its own. We
have studied this planet in depth and still have
no true clue as to the nature and functions that
it implores to do what it does. In ancient
cultures, the Earth was considered to be the
mother of creation and God the father. As it is
true for me and my beliefs. Earth is our home. |
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Earth is
the third planet from the Sun and is the largest of the
terrestrial planets in the Solar System, in both diameter
and mass. It is also referred to as the Earth, Planet Earth,
and the World, and in some contexts, Gaia and Terra.
Home to millions of species including humans, Earth is the
only place in the universe where life is known to exist.
Scientific evidence indicates that the planet formed 4.54
billion years ago, and life appeared on its surface within a
billion years. Since then, Earth's biosphere has
significantly altered the atmosphere and other abiotic
conditions on the planet, enabling the proliferation of
aerobic organisms as well as the formation of the ozone
layer which, together with Earth's magnetic field, blocks
harmful radiation, permitting life on land.
Earth's outer surface is divided into several rigid
segments, or tectonic plates, that gradually migrate across
the surface over periods of many millions of years. About
71% of the surface is covered with salt-water oceans, the
remainder consisting of continents and islands; liquid
water, necessary for all known life, is not known to exist
on any other planet's surface. Earth's interior remains
active, with a thick layer of relatively solid mantle, a
liquid outer core that generates a magnetic field, and a
solid iron inner core.
Earth interacts with other objects in outer space, including
the Sun and the Moon. At present, Earth orbits the Sun once
for every roughly 366.26 times it rotates about its axis.
This length of time is a sidereal year, which is equal to
365.26 solar days.[15] The Earth's axis of rotation is
tilted 23.4° away from the perpendicular to its orbital
plane, producing seasonal variations on the planet's surface
with a period of one tropical year (365.24 solar days).
Earth's only known natural satellite, the Moon, which began
orbiting it about 4.53 billion years ago, provides ocean
tides, stabilizes the axial tilt and gradually slows the
planet's rotation. A cometary bombardment during the early
history of the planet played a role in the formation of the
oceans. Later, asteroid impacts caused significant changes
to the surface environment. Long term periodic changes in
the Earth's orbit, caused by the gravitational influence of
other planets, are believed to have given rise to the ice
ages that have intermittently covered significant portions
of Earth's surface in glacial sheets.
Source
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http://en.wikipedia.org/wiki/Earth |
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71 Percent of the Earth's surface is covered with water.
Earth is the only planet on which water can exist in liquid
form on the surface (though there may be liquid ethane or
methane on Titan's surface and liquid water beneath the
surface of Europa). Liquid water is, of course, essential
for life as we know it. The heat capacity of the oceans is
also very important in keeping the Earth's temperature
relatively stable. Liquid water is also responsible for most
of the erosion and weathering of the Earth's continents, a
process unique in the solar system today (though it may have
occurred on Mars in the past).
The Earth's
atmosphere is 77% nitrogen, 21% oxygen, with traces
of argon, carbon dioxide and water. There was probably a
very much larger amount of carbon dioxide in the Earth's
atmosphere when the Earth was first formed, but it has since
been almost all incorporated into carbonate rocks and to a
lesser extent dissolved into the oceans and consumed by
living plants. Plate tectonics and biological processes now
maintain a continual flow of carbon dioxide from the
atmosphere to these various "sinks" and back again. The tiny
amount of carbon dioxide resident in the atmosphere at any
time is extremely important to the maintenance of the
Earth's surface temperature via the greenhouse effect. The
greenhouse effect raises the average surface temperature
about 35 degrees C above what it would otherwise be (from a
frigid -21 C to a comfortable +14 C); without it the oceans
would freeze and life as we know it would be impossible.
(Water vapor is also an important greenhouse gas.) Source -
http://www.nineplanets.org/earth.html |
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Please note that this site is strictly a hobby site. The authors of any pages do not have degree's nor wish to be accredited for any work. We are just stating that there is more out there than what you may realize. All information is food for thought.
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