Q
QuestionAstronomy

Use the information from the article to answer the question. Why is Pluto now called a dwarf planet?
11 months agoReport content

Answer

Full Solution Locked

Sign in to view the complete step-by-step solution and unlock all study resources.

Step 1:
I'll solve this problem by explaining the reclassification of Pluto as a dwarf planet:

Step 2:
: Understanding Planetary Classification

In 2006, the International Astronomical Union (IAU) established new criteria for defining a planet. To be considered a full planet, a celestial body must meet three key requirements:

Step 3:

It orbits the Sun

Step 4:

It has enough mass to achieve a nearly round shape (hydrostatic equilibrium)

Step 5:

It must have "cleared the neighborhood" around its orbit

Step 6:
: Pluto's Orbital Characteristics

Pluto fails the third criterion. While it orbits the Sun and is nearly spherical, it has not cleared its orbital neighborhood. Its orbit overlaps with many other objects in the Kuiper Belt, a region of icy bodies beyond Neptune.

Step 7:
: Creation of the Dwarf Planet Category

To accommodate celestial bodies like Pluto, astronomers created a new classification called "dwarf planet". This category includes objects that: - Orbit the Sun - Have sufficient mass to assume a nearly round shape - Have not cleared their orbital neighborhood - Are not satellites of other planets

Step 8:
: Specific Reasons for Pluto's Reclassification

- Pluto is much smaller than the other planets - It shares its orbital region with many similar-sized objects - Its mass is significantly less than the other eight planets - Its orbit is more elliptical and inclined compared to major planets

Final Answer

Pluto was reclassified as a dwarf planet because it does not meet all three criteria for a full planet, specifically failing to clear its orbital neighborhood, despite orbiting the Sun and being nearly spherical.