Inner Planets
This planet is closest to the Sun.
What is Mercury?
This is the largest planet in our solar system.
What is Jupiter?
In our toilet paper model, 1 square represented this many million km.
What is 10 million km?
This is the name of our galaxy.
What is the Milky Way?
This planet has the most moons in our solar system.
What is Saturn?
This is the only planet known to support life.
What is Earth?
This planet is famous for its beautiful rings made of ice and rock.
What is Saturn?
It took about this many toilet paper squares to reach Neptune.
What is 450 squares?
This is the largest thing in the universe (as far as we know).
What is the observable universe?
These planets are called "rocky planets" because they have solid surfaces.
What are Mercury, Venus, Earth, and Mars?
These four planets are called the rocky or inner planets.
What are Mercury, Venus, Earth, and Mars?
These four planets are called the gas giants and ice giants.
What are Jupiter, Saturn, Uranus, and Neptune?
These two planets are closest together in distance in our model.
What are Earth and Venus? (or Venus and Earth)
This is smaller than a cell and was found on the Scale of the Universe website.
What is an atom? / What is a molecule? / What is DNA? / What is a virus? (Accept any correct answer from the site.)
This planet is the hottest in our solar system.
What is Venus?
This planet is often called Earth's "twin" because it is similar in size, but it is much hotter.
What is Venus?
This planet is tilted on its side and rolls like a ball as it orbits the Sun.
What is Uranus?
This is why the outer planets are so much farther apart than the inner planets.
Why is the solar system so spread out? / Why are the outer planets farther apart? (Accept reasonable reasoning — e.g., "the solar system is mostly empty space," "gravity pulled more material closer to the Sun," etc.)
This is larger than our galaxy and contains many galaxies.
What is a galaxy cluster? / What is a supercluster? / What is the universe?
This type of graph is best for comparing the diameters of planets.
What is a bar graph?
This planet is called the "Red Planet" because of the iron oxide (rust) on its surface.
What is Mars?
This is the farthest planet from the Sun in our solar system.
What is Neptune?
If we changed the scale to 1 square = 50 million km, the model would be this.
What is smaller/shorter? (Accept: "It would take fewer squares," "Neptune would only be 90 squares away," etc.)
This is why scientists need to understand the scale of the universe.
Why is it important to understand the scale of the universe? (Accept: "To understand how big things are," "To study space," "To know our place in the universe," etc.)
This is one difference between gas giants and rocky planets.
What is "gas giants are much larger" / "gas giants have no solid surface" / "rocky planets are closer to the Sun"? (Accept any correct comparison.)