Illustration of Pluto alongside a text discussing its classification as a dwarf planet.

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 answering this question:

#### Step 1: Understand the Criteria
- According to the IAU, a planet must:
1. Orbit the sun.
2. Be large enough to have become round due to its own gravity.
3. Have cleared its orbit of other debris.

Pluto meets the first two criteria but fails the third because its orbit overlaps with other objects in the Kuiper Belt.

#### Step 2: Consider Different Perspectives
- Scientific Perspective: The IAU's definition is based on scientific criteria. Since Pluto does not clear its orbit, it is classified as a dwarf planet.
- Historical and Cultural Perspective: Some argue that Pluto should retain its status as a planet due to its historical significance and the emotional attachment many people have to it.
- Classification Flexibility: Owen Gingerich suggests a dual classification system, which could accommodate both "classical planets" and "dwarf planets."

#### Step 3: Formulate Your Opinion
Based on the information provided, here are two possible answers:

1. Supporting the IAU's Decision:
- Pluto should be classified as a dwarf planet because it does not meet all the criteria set by the IAU. The scientific community has established these guidelines to maintain consistency in planetary classification.

2. Arguing for Pluto as a Planet:
- Pluto should remain a planet due to its historical significance and the fact that it orbits the sun and is round. The current classification system could be revised to include a broader definition that accommodates Pluto's unique characteristics.

Final Answer:

Depending on your perspective, you can choose either option. Here’s a sample response:

Answer:
I believe Pluto should be classified as a dwarf planet. While it has significant historical and cultural importance, the IAU's definition of a planet is based on scientific criteria that Pluto does not fully meet. By adhering to these criteria, we maintain consistency in our understanding of the solar system. However, recognizing Pluto's unique role in history and science could involve acknowledging it as a special type of dwarf planet, as suggested by Owen Gingerich.

Final Answer Box:
\boxed{\text{Dwarf Planet}}