Pluto: The Planet that Wasn't

Pluto used to be considered a planet, what is it considered today?

• Dwarf planet

• star

• comet

• asteroid

How does the test describe Pluto?

• made up entirely of ice, and is bigger than Venus

• made up entirely of rock and ice, bigger than Earth's moon

• made up entirely of gas, is bigger than Earth's moon

• made up entirely of rock and ice, smaller than Earth's moon

Either Eris was the 10th planet in the solar system or it was not a planet at all! And if Eris weren’t a planet, could Pluto be considered one?

Scientists made new rules for what is counted as a planet, and decided that neither Pluto nor Eris qualified.

Based on this information, what did the discovery o Eris make scientists do?

• rethink the rules of what is counted as a star

• rethink the rules of what counted as a dwarf planet

• rethink the rules of what counted as a planet

After Eris was discovered scientists had to decide whether to count it as a planet.

Why did this make them look at Pluto as well.

• Pluto and Eris are both space objects

• Pluto and Eris were discovered at same time

• Pluto and Eris were different

• Pluto and Eris were similar

What is the main idea of this text?

• Pluto was no longer a planet after the discovery of Eris made scientists develop new rules to identify planets

• Pluto is so far away from Earth it took almost 10 years to get close to it

• Scientists develop new rules for what is counted as a planet

Pluto and Eris became members of the dwarf planet club. So long for Planet Pluto—but at least it no longer has to be the littlest guy in the club. In fact, Pluto is one of the bigger dwarf planets! Maybe Pluto doesn’t have it so bad after all.

What does the author mean by stating, "Maybe Pluto doesn't have it so bad after all?

• Pluto is in a new group called Dwarf planets

• Pluto is one of the bigger dwarf planets

• Pluto is not alone in space

Choose the best answer to complete the sentence:

After scientists made new rules for what is counted as a planet, Pluto was no longer considered a planet. _________, the official list of planets in the solar system went from nine to eight.

• Therefore

• Although

• On the other hand

• Especially