UNIT 1. PLANET EARTH
SESSION 1. THE UNIVERSE
The Universe
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You have to Know…
The universe was formed some 13.700 million years ago.
It was the
result of an explosion (the Big Bang*)
of a small mass that contained all existing matter and energy.
The Universe
is formed of stars and celestial bodies,
interstellar matter (dust and gas) and the space that
separates all these elements.
When a group
of stars are together, we call them galaxies.
For example the Milky way** is the
galaxy that contains the Earth. The galaxies contain millions of stars and many
planetary systems. These planetary
systems consist of a number of celestial bodies (planets, satellites, asteroids and comets) that move around a star.
The solar system is the planetary system to
which the Earth belongs. It was
formed around 5000 million years ago
and includes the Sun, which is a star, eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune and
numerous satellites, asteroids and comets.
We can say
that the Earth is a tiny dot in the
immense universe.
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Additional information…
*Fred Hoyle
first mentioned the Big Bang theory
on his radio show. He didn’t believe in this theory, but scientists who didn’t
agree with him, thought the name was funny and decided to use it. Since then,
Fred Hoyle’s reasons for not agreeing with the Big Bang theory have been proven
wrong.
**The name
Milky way is derived from its Latin name: Via
Lactea, which means the road of milk. The Romans got the name from the
Greeks and it’s because our galaxy looks like a band of milky lights over a
black background.
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Vocabulary:
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Planet: An astronomical body that goes around a star
and which doesn’t have its own light. (Example: the Earth is a planet that goes
around the Sun)
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Satellites: They are bodies without light that
go around a planet. (Example: the Moon
is a satellite that orbits around the Earth.
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Orbit: The path of an astronomical body in space.
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Star: A celestial body that has their own light.
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Planets: They are bodies without their own
light that circle a star (For example: The Earth goes around the Sun)
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Universe: It consists in all the celestial
bodies that exist in space. Includes stars, planets, satellites, interstellar
matter and the space that separates these elements.
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Exercises:
1.
Learn
and make a sentence with each of the following words: Star / Planet /
Satellite/ Universe.
2.
Order
the list of planets from the closest to the furthest from the Sun.
3.
Chose
three planets of our Solar System and write three characteristics about them.
( from video).
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Investigator’s
corner:
1.
According
to Greek mythology, the goddess Hera was the creator of the Milky Way. Find
more information about this myth and write a short summary in your notebook.
2.
Search
for information about Pluto….Why nowadays is not considered as the ninth planet
of our solar system?
