Exploring the Universe's Features

Which of the following best describes a galaxy?

• A large cloud of gas and dust in space

• A system of millions or billions of stars, together with gas and dust, held together by gravity

• A small rocky object orbiting a planet

• A single star and its planets

What is the main difference between a star and a planet?

• Stars are made of rock, planets are made of gas

• Stars produce their own light, planets reflect light from stars

• Planets are larger than stars

• Planets are found only in other galaxies

Which of the following is NOT a feature of a nebula?

• It is a region of space filled with gas and dust

• It is often a birthplace of new stars

• It is a solid, rocky body

• It can be seen as colourful clouds through telescopes

Which of the following best describes a moon?

• A star that has burnt out

• A natural satellite that orbits a planet

• A small galaxy

• A cloud of gas and dust

What is the Solar System?

• A group of galaxies

• The Sun and all the objects that orbit it, including planets, moons, asteroids, and comets

• A single planet and its moons

• A cluster of stars

Which of the following is the correct order from smallest to largest?

• Planet, Moon, Star, Galaxy, Solar System

• Moon, Planet, Star, Solar System, Galaxy

• Star, Moon, Planet, Galaxy, Solar System

• Moon, Star, Planet, Solar System, Galaxy

Approximately how many kilometres are in one light year?

What does a light year measure?

• Time

• Distance

• Speed

• Brightness

Which of the following is a strength of using models to represent the universe?

• Models can show every detail of the universe

• Models help us understand complex systems by simplifying them

• Models are always completely accurate

• Models never need to be updated

What is a limitation of using models to represent the universe?

• Models can be used to make predictions

• Models can be easily changed

• Models may not include all details or may oversimplify

• Models are always correct