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How Was the Solar System Formed?
By Patti Hutchison
How did the solar system form? Scientists have studied this question for
many years. They have learned much from studying our own planet and
solar system. They have also studied other solar systems in the universe
to find clues.
Today, scientists generally believe our solar system began about 4.6
billion years ago. It started out as a spinning cloud of gas and dust.
Something caused the materials to begin to clump together. Scientists
think maybe it was a shockwave from a supernova.
A supernova is a highly energetic explosion. It occurs at the end of a
star's life. Its nuclear fuel is gone, and it does not release any more
nuclear energy. The core of the star collapses and releases a huge
amount of energy. Scientists believe this was the shock that made the
material in the cloud come together.
Smaller particles bunched together, forming larger objects. The density
became greater in the center of the huge cloud. The cloud flattened like a disk because of the constant spinning
motion.
As the disk continued to spin over millions of years, the mass in the center continued to grow. The temperature
increased. Eventually it caught fire, and nuclear fusion began. This event was the birth of our Sun.
The disk continued to spin. It contained all the gas and dust that did not go into the formation of the sun. In this
spinning cloud were minerals, water, and organic molecules such as methane. The materials continued to collide,
forming larger and larger bodies. Eventually they formed the rocky inner planets. These include Mercury, Venus,
Earth, and Mars. They are the closest planets to the sun.
Farther from the Sun, the temperature was very cold. Water froze into ice. Chunks of ice bumped into each other.
Gas and dust were swept along. Eventually, the gas giant planets were formed. They include Jupiter, Saturn,
Uranus, and Neptune.
Farther out in space, there was not as much matter. There were not as many collisions. Objects that were formed
were smaller than the planets. The Oort Cloud and the Kuiper Belt are in this region of the solar system. Here is
where the dwarf planets, comets, and other icy objects exist.
We now know our solar system to contains eight planets. There are also dwarf planets. We know of 140 moons, as
well as numerous comets and asteroids. It is a remarkable place.
Scientists have studied the cosmos for thousands of years. They once believed that the Earth was the center of the
universe with the sun and all the planets revolving around it. Little by little, we are charting the universe. Space
missions are constantly finding out more about what's out there and how it got there.
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Date
How Was the Solar System Formed?
Questions
1. A highly energetic explosion at the end of a star's life is called:
A. the cosmos
B. an asteroid
C. a supernova
2. The temperature increase in the middle of the spinning disk of dust caused the formation of:
A. asteroids
B. clouds
C. the Sun
3. Minerals, water, and organic materials formed the:
A. the rocky inner planets
B. gas giant planets
C. the Sun
4. Name the four gas giant planets.
5. Why were objects that formed farther out in space smaller than the planets?
6. How many moons do we know of in the solar system?
A. 140
B. 8
C. 4.6 billion
Tell in your own words how the rocky inner planets were formed.
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Find out more about supernovas. Write a paragraph.
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