Transcript The Evolution of the Solar System

The Evolution of
the
Solar System
By: Saroeun Son
• It is believed that the solar system and all
the other solar system all originated from
the big bang. The big bang happened about
20 billion years ago. It was an explosion
where all hot matter was sent throughout
the universe. These violent explosions, as
implied by the Big Bang theory, continue to
explode to this day expanding our universe.
• As the matter cools down, they formed many galaxies
and stars. About 4.5 billion years ago our star, the Sun,
was born. This was the beginning of our solar system.
Our galaxy, the Milky Way, is one of the many galaxies
that were formed. Inside the Milky Way, we have
many stars, solar systems, and other types of space
matter being created.
How the Big Bang Theory was
Implied
The big bang theory assumes that the
universe began from a singular state of
infinite density. This means that the
universe started off as a single state
and continues to expand to this day.
But how was it started? Eintein had
believed that the universe is still
expanding as the world went on, and
from this he created an equation to
explain its expansion. Einstein did not
finish his equation, but a scientist
named Alexander Friedmann
completed his equations in 1922.
How the Big Bang Theory was
Implied
• Then in 1927, George
Lemaitre used the
equations to devise a
theory that had the
concept of the
universe expanding.
George Gamow and
R.A. Alpher named
the theory “Big Bang.”
This is how the term
“Big Bang” came to be.
Birth Of The Solar System
• Scientists assumed that around 4.6 billion years ago, in
the darkness of space, a large cloud of gas and dust
once spun round like a huge flat disk, millions and
millions of kilometers across. This huge cloud was
known as a nebula, and most of the gas in the nebula
was hydrogen.
Birth Of The Solar System
• Many years later, the spinning nebula collapsed under
gravity and compressed to form a rotating gas globule.
The gravity of the spinning nebula pulled together a
massive, tightly packed lump, shaped like a ball. The
process of the collapse took about 10 thousand to 1
million years.
Birth Of The Solar System
• As the collapse continued, the temperature and
pressure within the globule increases. In time it
became a spinning disc, with most matter
concentrated in the center. The central core
continued to collapse under gravity, becoming
smaller and hotter. When the core reached the
temperature of about 27, 000, 000, 000 F, a nuclear
fusion began and our Sun was born.
Birth Of The Solar System
• As soon as the Sun was ignited with its fires, it
released solar winds that pushed the surrounding dust
and gases all around areas. Grains of dust collided and
formed bigger and bigger lumps. Some of these lumps
crashed together and formed planets, drawn together
under gravity. The four solid rock planets, Mercury,
Venus, Earth, and Mars were created. In the outer
regions of the disk, the solar wind was weaker. The
remaining dust and gas condensed into the larger
gaseous planets: Jupiter, Saturn, Uranus and Neptune.
Birth Of The Solar System
• Between the orbits of Mars and Jupiter there is a
relatively large gap in the solar system, where you
might expect to find a planet. But instead there is a
swarm of much smaller bodies, called asteroids, or
minor planets. This area is called the Asteroid Belt.
Around 2500 of these bodies have been discovered,
and are usually just chunks of rock measuring a few
kilometers across. Most of them have an orbit around
the Sun between Mars and Jupiter, but some have
orbits farther out or closer in, sometimes quite near to
the Earth.
The Brightness of the Sun
• As the new star grew
larger and became more
tightly packed, the gas
at its center became
very hot, making the Sun
shine more brightly. But
like any other star, the
Sun cannot keep shining
forever.
• As far as scientist can
tell, it has been shining
for about 4.6 billion
years and it is about
halfway through its life
span. This means that
the Sun should keep
shining for about
another 4.6 billion years,
if it keeps shining as it
does today.
The Brightness of the Sun
• The Sun shines by fusing hydrogen into helium.
Since there is limited amount of hydrogen in the
Sun’s core region to serve as fuel for shining, the
Sun must stop shining as we see it today when it
uses up its core hydrogen fuel supply.
• The Sun is able to keep shining throughout a very
long life span of billion years, because it takes very
little mass of hydrogen nuclei to produce an
enormous amount of energy.
Life on Earth
• Scientists have believed that life on our planet,
Earth, began about three and a half billion years
ago. That was only one billion years after the Earth
was formed. The first plants and animals lived in
the oceans. Then, over 400 million years ago, living
things appeared on dry land. Dinosaurs appeared
200 million years, and human beings didn’t develop
until 198 million years after that.
The End