Understanding Dwarf Planets and Their Significance

What is the main idea of the passage?

• Dwarf planets are fun to look at.

• Dwarf planets are small worlds that go around the Sun and help scientists learn about space.

• Pluto is the largest planet in space.

• Dwarf planets are the same as moons.

Which of these is a detail from the passage?

• Dwarf planets live only near Earth.

• Pluto is the only dwarf planet.

• Ceres is a dwarf planet in the asteroid belt.

• Dwarf planets are made of ice cream.

Why was Pluto changed from being a planet to a dwarf planet?

• It moved closer to the Sun.

• It got smaller over time.

• Scientists found other objects like Pluto and made new rules.

• Pluto disappeared from space.

Which of these objects is a dwarf planet?

• Mars

• Earth

• Jupiter

• Eris

What is the best summary of the passage?

• Dwarf planets are fake planets that look like stars.

• Dwarf planets orbit the Sun, are round, and share space with other objects. Pluto was changed to a dwarf planet after scientists found others like it.

• All planets were changed to dwarf planets in 2006.

• Scientists no longer study space.

What makes a planet a "dwarf planet"?

• A dwarf planet is the only one near the Sun.

• A dwarf planet is big and very hot.

• A dwarf planet goes around the Sun, is round, and shares space with other objects.

• A dwarf planet is smaller than the Moon.

Why is Ceres different from other dwarf planets?

• It is rounder than the others.

• It is the only one found near Earth.

• It is found in the asteroid belt between Mars and Jupiter.

• It was never called a planet.

How did scientists change the way they think about Pluto?

• They said it was no longer part of space.

• They decided Pluto was too small to matter.

• They changed it to a dwarf planet after finding similar objects.

• They made Pluto a star.

What happened in 2006 that was important?

• All dwarf planets became stars.

• The Sun moved closer to Earth.

• Scientists made a rule about what counts as a planet.

• Pluto became the biggest planet.

Why do dwarf planets help scientists understand more about space and how our solar system works?

• Because they are bigger than the Sun.

• Because they tell us how Earth was made.

• Because they show that space has many kinds of small worlds, not just planets.

• Because they help spaceships go faster.