Download What is the source of the sun`s energy?

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A star begins its formation in a cloud of
hydrogen and helium gas referred to as a
nebula.
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The material blown off by a supernova
explosion ultimately scatters throughout
space, and some of it is incorporated in
clouds of dust and gas which later form new
suns and planets.
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The material from which the solar system
formed, must have been the cloud of dust
and gas left from a supernova and gradually
pulled together by gravity.
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Astronomers have observed (using the
Hubble telescope, among others), disks of
swirling dust which presumably mark the
birth of other planetary systems.
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This is an important question, and one that is difficult
for scientists to understand.
The creation of our Solar System took place billions of
years before there were any people around to witness
it.
Scientists believe that the Solar System evolved from
a giant cloud of dust and gas. They believe that this
dust and gas began to collapse under the weight of its
own gravity. As it did so, the matter in this could begin
moving in a giant circle, much like the water in a drain
moves around the center of the drain in a circle.
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At the center of this spinning cloud, a small star begin
to form. This star grew larger and larger, as it collected
more of the dust and gas that were collapsing into it.
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Further away from the star that was forming in the
center were smaller clumps of dust and gas that were
also collapsing.
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The star in the center eventually ignited forming our
Sun, while the smaller clumps became the planets,
minor planets, moons, comets, and asteroids.
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Once ignited, the Sun's powerful solar winds
began to blow.
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These winds, which are made up of atomic
particles being blown outward away from the
Sun, slowly pushed the remaining gas and
dust out of the Solar System.
• It's a crucial question, because light and heat from the sun are the basis of (almost)
all life on earth.
•Sunlight drives plant life via photosynthesis, and animals survive by eating plants.
•Almost all microscopic forms of life (bacteria, protozoa, etc.) survive by using the
energy of sunlight.
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Heat is the motion of atoms and molecules: the higher
the temperature, the greater is their velocity and the more
violent are their collisions.
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When the temperature at the center of the newly-formed
Sun became great enough for collisions between nuclei to
overcome their electric repulsion, nuclei began to stick
together and protons were combined into helium.
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This released nuclear energy and kept up the high
temperature of the Sun's core, and the heat also kept the
gas pressure high, keeping the Sun puffed up and stopping
gravity from pulling it together any more.
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That, in greatly simplified terms, is the
"nuclear fusion" process which still takes
place inside the Sun.
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Nuclear fusion is how stars produce their
light, heat, and energy. Through this process,
they “burn” a fuel known as hydrogen.
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The result is that they create another type of
matter known as helium.
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However, stars do not burn in the same way
that a fire does, because stars are not on fire.
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With no more gas or dust, the planets, minor
planets, moons, comets, and asteroids
stopped growing.
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You may have noticed that the four inner
planets are much smaller than the four
outer planets. Why is that?
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Because the inner planets are much closer to the
Sun, they are located where the solar winds are
stronger.
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As a result, the dust and gas from the inner Solar
System was blown away much more quickly
than it was from the outer Solar System.
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This gave the planets of the inner Solar System
less time to grow.
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Astronomers like to categorize the planets
into two categories.
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The first category is the terrestrial planets.
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The second category is the Jovian planet
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The terrestrial planets include Mercury,
Venus, Earth, and Mars.
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These planets have solid surfaces, with the
last three also having an atmosphere.
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Their size, radius, and density are all similar.
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The outer planets have a lot of atmosphere.
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Below the surface, hydrogen and helium are in a liquid form.
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At the center is a rocky core.
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Each of these huge planets has its own system of moons.
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Rings around Saturn have been seen for many years. They are
probably made mostly of water, ice, and other icy particles.
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Rings have been discovered around two more giant planets —
Jupiter and Uranus. Scientists expect to find rings around
Neptune, too.
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Another important difference is that the
outer planets are made up largely of gas,
and water, while the inner planets are made
up almost entirely out of rock and dust.
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This is due to the same reasons. As the outer
planets grew larger, their gravity had time to
accumulate massive amounts of gas, water,
as well as dust.
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There is a very great distance between the inner and outer
planets.
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This region is called the Asteroid Belt and large chunks of rock
swarm around and around in it.
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Except for Pluto, the outer planets are alike in a lot of ways.
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They are much bigger than the inner planets.
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They are made mostly of hydrogen and helium.
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The hydrogen and helium are in the form of gas in the planets'
atmospheres.
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The Jovian planets include Jupiter, Saturn, Uranus, and Neptune.
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These planets are also called gas giants.
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They are much larger in radius than the terrestrial planets, and the
majority of their volume is composed of gas mostly hydrogen and
helium gas. Small amounts of other gases also appear and are
likely the reason for the various Jovian colors.
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The structure of all Jovian planets, is layered.
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The central layer is a solid core.
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Surrounding the core is a mantle of liquid metallic hydrogen.
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Outside this mantle is a layer of hydrogen and helium gas.
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Terrestrial planets are
small, rocky, low
surface gravity and
have short years.
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Jovian planets are
large, gaseous, high
surface gravity and
have long years.
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Moon rock solidified from magma before
Earth's crust had formed. A rock's age is
determined from its point of solidification.
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Geologists would use some form of
radiometric dating.
EARTH CHANGES
Earths process include
all of the forces that
combined to form the
landform.
These processes might
be weather, pressure,
water, wind, moving
sheets of ice, etc.
All landforms are being
changed by the many
different forces that
are constantly at work
on them.
The Earth as been evolving and changing for many
hundreds of millions of years, even billions of years.
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The changes that take place in the Earth’s landscape are
usually very slow by human standards. It takes many
generations of lifetimes before any noticeable changes
have taken place in the landscapes of a particular location.
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Yet, in geologic time, the Earth is constantly changing and
evolving. What we see today will be very different in the
future. The mountains, rivers, lakes, and land formations
of today will not exist at some point in the distant future.
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What is a nebula?
What is the source of the sun's energy?
What is the process which still takes
place inside the Sun.
Where did the material come from to
make a solar system?
What is a supernova?
The four inner planets are also known as
the ________ planets.
Why are the four inner planets much
smaller than the four outer planets?
Name the terrestrial planets
Name the outer planets
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Why are the outer planets larger?
What planets are also called gas giants?
What are the 4 main differences
between the terrestrial and Jovian
planets?
There is a very great distance between
the inner and outer planets. What lies
between this vast space?
Why are moon rocks older than earth
rocks?