Mind blowing facts about EARTH
DID YOU KNOW ?
1. Plate Tectonics
Keep the Planet Comfortable:
Earth is the only
planet in the Solar System with plate tectonics. Basically, the outer crust of
the Earth is broken up into regions known as tectonic plates. These are
floating on top of the magma interior of the Earth and can move against one
another. When two plates collide, one plate will sub duct (go underneath
another), and where they pull apart, they will allow fresh crust to form.
This process is very important, and for
a number of reasons. Not only does it lead to tectonic resurfacing and
geological activity (i.e. earthquakes, volcanic eruptions, mountain-building,
and oceanic trench formation), it is also intrinsic to the carbon cycle. When
microscopic plants in the ocean die, they fall to the bottom of the ocean.
Over long periods of time, the remnants of this life, rich in
carbon, are carried back into the interior of the Earth and recycled. This
pulls carbon out of the atmosphere, which makes sure we don’t suffer a runaway
greenhouse effect, which is what happened on Venus. Without the action of
plate tectonics, there would be no way to recycle this carbon, and the Earth
would become an overheated, hellish place.
2. Earth is Almost a Sphere:
Many people tend to think that the Earth is a sphere. In fact,
between the 6th century BCE and the modern era, this remained the scientific
consensus. But thanks to modern astronomy and space travel, scientists have
since come to understand that the Earth is actually shaped like a flattened
sphere (aka. an oblate spheroid).
This shape is similar
to a sphere, but where the poles are flattened and the equator bulges. In the
case of the Earth, this bulge is due to our planet’s rotation. This means that
the measurement from pole to pole is about 43 km less than the diameter of
Earth across the equator. Even though the tallest mountain on Earth is Mount
Everest, the feature that’s furthest from the center of the Earth is actually Mount Chimborazo in Ecuador.
3. Earth is Mostly
Iron, Oxygen and Silicon:
If you could separate
the Earth out into piles of material, you’d get 32.1 % iron, 30.1% oxygen,
15.1% silicon, and 13.9% magnesium. Of course, most of this iron is actually
located at the core of the Earth. If you could actually get down and sample the
core, it would be 88% iron. And if you sampled the Earth’s crust, you’d find
that 47% of it is oxygen.
4. 70% of the Earth’s Surface is covered in Water:
When astronauts first
went into the space, they looked back at the Earth with human eyes for the
first time. Based on their observations, the Earth acquired the nickname the
“Blue Planet:. And it’s no surprise, seeing as how 70% of our planet is covered
with oceans. The remaining 30% is the solid crust that is located above sea
level, hence why it is called the “continental crust”.
5. The Earth’s
Atmosphere Extends to a Distance of 10,000 km:
Earth’s atmosphere is
thickest within the first 50 km from the surface or so, but it actually reaches
out to about 10,000 km into space. It is made up of five main layers – the
Troposphere, the Stratosphere, the Mesosphere, the Thermosphere, and the
Exosphere. As a rule, air pressure and density decrease the higher one goes
into the atmosphere and the farther one is from the surface.
Earth, as viewed from the cabin of
the Apollo 11 spacecraft. Credit: NASA
The bulk of the
Earth’s atmosphere is down near the Earth itself. In fact, 75% of the Earth’s
atmosphere is contained within the first 11 km above the planet’s surface.
However, the outermost layer (the Exosphere) is the largest, extending from the
base – located at the top of the thermosphere at an altitude of about
700 km above sea level – to about 10,000 km (6,200 mi). The
exosphere merges with the emptiness of outer space, where there is no
atmosphere.
The exosphere is
mainly composed of extremely low densities of hydrogen, helium and several
heavier molecules – including nitrogen, oxygen and carbon dioxide. The atoms
and molecules are so far apart that the exosphere no longer behaves like a gas,
and the particles constantly escape into space. These free-moving particles
follow ballistic trajectories and may migrate in and out of the magnetosphere
or with the solar wind.
6. The Earth’s Molten
Iron Core Creates a Magnetic Field:
The Earth is like a
great big magnet, with poles at the top and bottom near to the actual
geographic poles. The magnetic field it creates extends thousands of kilometers
out from the surface of the Earth – forming a region called the “magnetosphere“. Scientists think that this magnetic field is generated by the
molten outer core of the Earth, where heat creates convection motions of
conducting materials to generate electric currents.
Be grateful for the
magnetosphere. Without it, particles from the Sun’s solar wind would hit the
Earth directly, exposing the surface of the planet to significant amounts of
radiation. Instead, the magnetosphere channels the solar wind around the Earth,
protecting us from harm. Scientists have also theorized that Mars’ thin
atmosphere is due to it having a weak magnetosphere compared to Earth’s, which allowed solar wind to slowly strip it away.


how great facts
ReplyDelete