Reading Comprehension Worksheet - Is Pluto a Planet? - Free Printable

Problem Overview:

The passage discusses the debate surrounding whether Pluto should be classified as a planet or a dwarf planet. It provides information about the International Astronomical Union (IAU) definition of a planet, which excludes Pluto due to its size and orbit characteristics. The text also includes perspectives from scientists who disagree with this classification.

Key Points from the Passage:

1. IAU Definition of a Planet:
- A full-fledged planet must orbit the sun.
- It must be large enough to have become round due to its own gravity.
- Pluto does not meet these criteria and is thus classified as a dwarf planet by the IAU.

2. Disagreement with the Classification:
- Andy Cheng argues that the new rules are unclear and maintains that Pluto should still be considered a planet.
- Owen Gingerich supports a special distinction for Pluto, suggesting two classes of planets: "classical planets" (the big eight) and "dwarf planets" (Pluto and others).

3. Cultural and Historical Significance:
- Gingerich believes reclassifying Pluto as a dwarf planet is not sensitive to its historical and cultural role.

4. Current Status:
- Many people accept the IAU's decision, and new textbooks list Pluto as a dwarf planet.

Solution and Explanation:

The question at the end of the passage asks, "What do you think it is?" This is an open-ended question inviting personal opinion based on the information provided. Here’s how one might approach forming an opinion:

#### Option 1: Support Pluto as a Dwarf Planet
- Reasoning: The IAU's definition is scientifically rigorous and based on clear criteria. Pluto does not meet the size and gravitational requirements to be classified as a full-fledged planet. Its orbit is irregular compared to the other planets, and it shares characteristics with other objects in the Kuiper Belt.
- Conclusion: Pluto should be classified as a dwarf planet because it aligns with the scientific standards set by the IAU.

#### Option 2: Support Pluto as a Planet
- Reasoning: Pluto has been historically recognized as a planet for many years, and changing its status could undermine its cultural and educational significance. Additionally, the IAU's definition may be too rigid, as it does not account for the unique characteristics of Pluto.
- Conclusion: Pluto should retain its status as a planet due to its historical and cultural importance, even if it does not fully meet the IAU's criteria.

#### Option 3: Support a Special Distinction
- Reasoning: Owen Gingerich's proposal to create two classes of planets—classical planets and dwarf planets—acknowledges Pluto's unique place in our solar system. This approach respects both the scientific criteria and Pluto's historical significance.
- Conclusion: Pluto should be classified as a dwarf planet but given a special distinction to recognize its historical and cultural role.

Final Answer:

The answer depends on your perspective. Here are three possible responses:

1. Pluto is a Dwarf Planet:
- Based on the IAU's scientific criteria, Pluto does not meet the requirements to be classified as a full-fledged planet. Therefore, it should be classified as a dwarf planet.

2. Pluto is a Planet:
- Despite not meeting the IAU's criteria, Pluto has historical and cultural significance that warrants retaining its status as a planet.

3. Pluto is a Dwarf Planet with a Special Distinction:
- Pluto should be classified as a dwarf planet but acknowledged separately to reflect its unique role in our understanding of the solar system.

Final Answer (Example):
\boxed{\text{Pluto is a Dwarf Planet}}

This response aligns with the IAU's scientific criteria, which are widely accepted in the scientific community. However, feel free to choose any of the options based on your personal reasoning!