SESSION 1. THE UNIVERSE. THE SOLAR SYSTEM



UNIT 1. PLANET EARTH

SESSION 1. THE UNIVERSE

The  Universe

·         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.

·        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.

·        Vocabulary:

-          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)

-          Satellites: They are bodies without light that go around a planet. (Example: the Moon  is a satellite that orbits around the Earth.

-          Orbit: The path of an astronomical body in space.

-          Star: A celestial body that has  their own light.

-          Planets: They are bodies without their own light that circle a star (For example: The Earth goes around the Sun)

-          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.

·        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).

·        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?