The reading comprehension passage titled
"Is Pluto a Planet?" discusses the ongoing scientific debate about whether Pluto should be classified as a planet. Let's break down the key points and then provide an explanation of the solution to the implied task.
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🔍 Summary of the Passage:
1.
Official Classification (IAU):
- According to the
International Astronomical Union (IAU), a full-fledged planet must:
- Orbit the Sun.
- Be large enough for its own gravity to make it round (hydrostatic equilibrium).
- Have cleared its orbit of other debris.
- Pluto
does not meet the third criterion, so it is classified as a
dwarf planet.
2.
Scientific Debate:
- Some scientists
disagree with this classification.
-
Andy Cheng (planetary scientist) says the definition is unclear — especially regarding how "round" something must be — and believes Pluto should still be considered a planet.
-
Owen Gingerich (astronomer and historian), who helped propose the IAU definition, suggests a
special distinction for Pluto. He supports calling the original eight planets "classical planets" and Pluto a "dwarf planet," acknowledging Pluto’s cultural and historical significance.
3.
Current Status:
- Most new textbooks now list Pluto as a
dwarf planet.
- The debate continues, but the official stance remains that Pluto is
not a planet under the current IAU definition.
4.
Final Question:
- The passage ends by asking: *"What do you think it is?"* — prompting readers to form their own opinion based on the information.
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✔ Answering the Task (Implied Question):
Is Pluto a planet?
>
Based on the International Astronomical Union (IAU) definition, Pluto is NOT a planet; it is classified as a dwarf planet.
However, the article highlights that
this decision is controversial. While Pluto orbits the Sun and is nearly round due to gravity, it has
not cleared its orbital neighborhood of other objects — a key requirement for full planetary status.
Still, some scientists argue that the rules are too strict or vague, and that Pluto’s
historical and cultural importance should be considered.
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🧠 Explanation of the Solution:
- The
main idea of the passage is that Pluto’s status as a planet is debated.
- The
evidence comes from:
- The IAU's official definition.
- Opinions from experts like Andy Cheng and Owen Gingerich.
- The
conclusion is that while Pluto is officially a
dwarf planet, many people still consider it a planet due to emotional and historical reasons.
So, the
correct answer depends on perspective:
-
Scientifically: Pluto is
not a planet.
-
Culturally/Emotionally: Many still view Pluto as a planet.
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💬 Final Answer (for a student response):
> No, according to the International Astronomical Union (IAU), Pluto is no longer classified as a planet. It is now considered a dwarf planet because it hasn't cleared its orbit of other objects. However, some scientists and people still believe Pluto should be called a planet due to its history and size. So, while the official answer is no, the debate continues.
This response shows understanding of both the
scientific facts and the
ongoing controversy — which is what the passage encourages readers to consider.
Parent Tip: Review the logic above to help your child master the concept of 6 grade reading worksheet.
