Question

Which one of the following planets lost its planet status recently?

• A. Moon
• B. Neptune
• C. Pluto
• D. Saturn

Hint:

Think about the 2006 decision that created a new category called dwarf planet.

Answer 1

The Correct Option is C

Step 1: Recall the 2006 planet definition.
In 2006, the International Astronomical Union laid down three conditions for a full planet: it must orbit the Sun, be nearly round due to its own gravity, and have cleared other objects from around its orbit.

Step 2: Test Pluto against this definition.
Pluto orbits the Sun and is round, but it shares its orbital zone in the Kuiper Belt with many other icy bodies, so it fails the third condition.

Step 3: Confirm the other bodies are unaffected.
Neptune and Saturn both clear their orbits and keep their planet status. The Moon was never counted as a planet since it orbits Earth, not the Sun, so it cannot lose a status it never had.

Final Answer:
Pluto is the body reclassified as a dwarf planet in 2006, so option C is correct. \[ \boxed{\text{Pluto}} \]