How Earth was formed,
its history, its present and how humans might affect
its future
Dr.
Abhinandan Bhardwaj PhD
Our home planet Earth
is a wondrous place. If you look at it from space it is
one of the most beautiful planet in our solar system
and looks like a bright blue marvel orbiting around
the sun. Its not only the most beautiful but most
fascinating planet as well as its the only known planet
thus far which can sustain life. Earth was born as a
run-of-the- rocky sphere orbiting a fairly average
star, a series of lucky breaks have turned Earth
into a hospitable, ever changing planet with a huge
variety of landscapes and habitats. Earth is the
largest of the solar system's terrestrial planet's.
Like many of the other
planets, Earth's axis of rotation is titled to its
orbit, so instead of spinning around the Sun in an
upright position, our planet is instead titled over at
an angle of 23.5 degrees from vertical. The Earth's
tilt points in the same direction in space
regardless of its position on its orbit round the
Sun, so different regions of the planet receive
differing amounts of sunlight throughout the year.
This gives rise to the seasons on Earth.
How Earth Formed
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Air
And Water
While most of our
planet is composed of rocky materials similar to those
found in other terrestrial planets, they are capped by
unique thin layer of water and gas known as
hydrosphere and atmosphere. These elements helps shape
the environment and the continents with the help of forces of tectonics. Earths atmosphere and
surface water can survive because of its unique position
in the solar system. Earth's fast
rotation rate prevents one side of the planet from
becoming boiling
hot while the other from deep freeze, and a moderate axial tilt
ensures that both poles receives a reasonable amount of
sunlight throughout the year, preventing them from
extending their icy grasp towards the equator. All these
factors combine to create a planet where the surface
temperature generally is between the freezing and
boiling points of water. You can call it a mere
coincidence but this coincidence of the temperature
would be meaningless if Earth had no atmosphere. Without
atmosphere liquid water would simply boil off into the
vacuum of the space. And as we know it water is
essential component for this planet's ability to sustain
life. If there wasn't any water there wouldn't have been
any life.
Life
Thanks to remarkable series of lucky
chances, our small, rocky planet has given rise to
a spectacular range of environments
capable of supporting diverse form of
life and even intelligence. Earth's
suitability for life seems to be the
result of a bizarre series of
coincidences or perhaps definitive
evidence for the hand of a creator? But
on the other hand presence of life on
earth is as a result of its history
which has resulted in very fragile
balance between many natural phenomena's
in favor of sustaining life.
Around 425
million years ago, life began to make
its way onto our planet, gradually adapting
the conditions that it found there to
create the familiar environment of
today's world. Plants absorbed much of
the carbon dioxide as waste, creating
conditions for animals to thrive.
Fragile Planet
We need
to keep one thing in mind that to form a
planet which can support life, it took
billion's of years by nature to reach to a stage
where it could support life in a very
delicately balanced atmosphere. Every process
amazingly worked in perfection to make
it habitable which can not only support life
but make it evolve to a stage that it
can nurture and support intelligent life
like humans. But
what needs to be understood and
stressed is that everything
including the atmosphere is extremely delicately
balanced and any altercation to it can
lead to destruction of not only humans
but make this planet uninhabitable to
any kind of life like other planets in
our solar system.
Earth
has a variety of special factors that
allow for complex life to flourish on
its surface. To describe all of these
factors would be beyond the scope of
this article. We must realize that how
amazing it is and how lucky we are that
all these conditions made it possible
that we exist today. Most of conditions which made this
earth support life relied heavily on a
large amount of chance events. With the
mind-boggling number of planets in the
universe, it is almost ludicrous to
think that life exists only on Earth.
But what if we are the only ones? What
if these factors are so rare, that we
are that one-in-a-trillion chance? Its
any ones guess. So lets not do something
which leads to destruction of the very
delicate balance which supports life on
Earth.
After
the Big Bang, there was matter and anti-matter. The two
could have annihilated each other and canceled out, yet we are
here. So there must have been slightly more matter than
anti-matter, and this leftover matter is what our
universe is made up of today. Learn more about
origin of Solar system and Earth
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Life on Earth is a lucky
little fluke of nature. The rock record shows when plant
and animal groups appeared on earth. The earliest
creatures did not had any hard skeleton so its extremely
hard to know exactly when did microscopic life appeared
on earth. The first multicelled oxygen breathing
creature probably appeared about 1 billion years ago
after oxygen on earth was well established. By about 600
million years ago marine animals with shells had become
widespread. Roughly 500 million years back first animals
with backbone appeared this was fish. Soon after that
land plants started developing. Insects appeared about
300 millions years back and dinosaurs appeared about 200
million years back. First mammals also appeared during
same time around 200 millions years ago. Birds appeared
about 150 million years back. About 100 million years
ago both animals and birds were well established on
earth.
On a time scale of
billions of years, human beings has just arrived. The
most primitive human type is not more than 4 million
years old. Homo sapiens developed only half a
million years back. Nevertheless, we humans have had an
enormous impact on the earth, at least its surface, an
impact far out of proportion to the length of time we
have occupied it.
But what needs to be understood
here is that how difficult it is to form a planet like
earth which can support life at first place. And then
how difficult it is to make those conditions available
which can support basic life and also to evolve it
to an extent for millions of years to reach to a point
which can create and sustain intelligent life like
humans. Nature took billions of years to create this
miracle race by providing necessary conditions and
evolve it continuously to create intelligent race
like humans. But that
very nature's miracle is threatening its very creator
'The Nature" by its indiscriminate, senseless plundering
and continuous altering of its fragile atmosphere by
pumping millions of tons of unwanted gases with no care or guilt for its actions.
But little it knows that those vary alterations to
natural systems will eventually lead to its own
extinction.
Air
And Water