Objective: Describe and compare the components of the Solar System.

Name ______

Dwarf Planets: A New Way of Thinking about an Old Solar System

Below are listed Solar System objects. Determine if the object is a planet, dwarf planet, or an asteroid.

Does it Orbit the Sun? / Is it Round? / Has it cleared its neighborhood? / Is it a moon orbiting a planet? / Does it orbit inside the orbit of Jupiter?
Yes / Yes / Yes / No / No

Does it Orbit the Sun? / Is it Round? / Has it cleared its neighborhood? / Is it a moon orbiting a planet? / Does it orbit inside the orbit of Jupiter?
Yes / No / No / No / Yes

2. This object is…

a. a planet. c. an asteroid.

b. a dwarf planet.

Does it Orbit the Sun? / Is it Round? / Has it cleared its neighborhood? / Is it a moon orbiting a planet? / Does it orbit inside the orbit of Jupiter?
Yes / Yes / No / No / No

3. This object is…

a. a planet. c. an asteroid.

b. a dwarf planet.

Does it Orbit the Sun? / Is it Round? / Has it cleared its neighborhood? / Is it a moon orbiting a planet? / Does it orbit inside the orbit of Jupiter?
Yes / Yes / Yes / No / No

4. This object is…

a. a planet. c. an asteroid.

b. a dwarf planet.

What is a Planet, Dwarf Planet, and an Asteroid?

In August 2006, the International Astronomical Union developed a definition for a planet, dwarf planet, and asteroid.

A PLANET is a celestial body that…

·  orbits the Sun.

·  is round or almost round.

·  has cleared the neighborhood around its orbit.

·  is not a moon orbiting another planet.

A DWARF PLANET is a celestial body that…

·  orbits the Sun.

·  is round or almost round.

·  has not cleared the neighborhood around its orbit.

·  is not a moon orbiting another planet.

An ASTEROID (or minor planet)…

·  orbits the Sun inside the orbit of Jupiter.

·  is not round or almost round.

·  has not cleared the neighborhood around its orbit.

·  is not a moon orbiting another planet.

Dwarf Planets: A New Way of Thinking about an Old Solar System Key

1. a

2. c

3. b

4. a

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