The Solar System and Beyond notes pg.1

Our solar system includes the sun, eight planets and their moons, comets, large space rocks called asteroids, dwarf planets, and small space rocks called meteoroids. Beyond our solar system are stars and groups of stars called galaxies.

Important Facts About the Solar System

·         When ordering the universe from Greatest to Least:

  Universe, Galaxy (Milky Way), Solar System

·         The Milky Way galaxy includes the Sun and Solar System. It is our home galaxy.

·         All stars including the sun belong to our solar system

·         Stars release different amounts of light. Therefore, one star ALWAYS appears BRIGHTER than the others.

·         The sun’s appearance is due to its proximity to Earth.

The sun

The sun is an average size star at the center of our solar system. Everything in the solar system revolves around the sun. Everything is kept in orbit by the pull of the sun’s gravity.

v  The sun is a huge yellow ball made mostly out of hydrogen gas. This fiery ball produces the heat and light that stream 150 million kilometers through space to Earth.

Galaxies

A galaxy is a group of between one million and one trillion stars. Our sun and solar system are part of the Milky Way Galaxy. The Milky Way Galaxy contains 100 to 200 billion stars.

Gravity and Orbits

Gravity is a force that pulls objects toward each other. All objects produce a force of gravity. The more mass and object has, the greater its force of gravity. The sun has much more mass than Earth, so the sun’s gravity is much greater than Earth’s gravity.

Review Questions

1.What is our home galaxy called?

2.What type of gas is the sun made out of?

3.The sun is an _______________ sized star

4.Why does one star always appear brighter than others?

5.Which of these is the biggest?

Universe   Galaxy   Solar System

Check your answers by looking at the answer key in the comments section. Like and comment Yay! If you got all the questions right. BYE SCIENTISTS! J