Download Which Objects Represent the Eight Planets in Our

Name: ______________________________
Pd: _____
Ast: _____
Identifying the Planets:
Which Objects Represent the Eight Planets in Our Solar System?
Background: A star, along with the group of planets and other celestial bodies that are held by its gravitational
attraction and revolve around it, comprises a solar system. Our Solar System, centered around the Sun, contains eight
planets along with their moons, a number of dwarf planets, and countless other objects such as asteroids, meteoroids,
and comets. In the last 100 years, as technology has allowed scientists to look further and more clearly into space, our
understanding of our own Solar System has dramatically changed. One of the greatest changes in the way we think
about the Solar System is how we classify planets.
There are eight planets in our Solar System. The four inner planets (Mercury, Venus, Earth, & Mars) are referred to as
“terrestrial planets” due to their solid rocky make-up. They are relatively small compared to the four outer planets, the
“gas giants” (Jupiter, Saturn, Uranus, & Neptune). A ninth planet has been recognized off and on over the years. In
1801, a large spherical object was discovered beyond the orbit of Mars. It was named, Ceres, and was classified as a
planet until the 1850’s when many other objects were discovered in what became known as the Asteroid Belt. In 1930,
another large spherical object was discovered beyond the orbit of Neptune. Scientists named it, Pluto, and it was
recognized as a planet for nearly 80 years. However, upon the discovery of many other large objects beyond the orbit of
Neptune at the beginning of this century, scientists began to question what actually constitutes a “planet”.
In 2006, the International Astronomical Union met to debate the topic of planet classification. This group developed a
new, scientifically accepted definition of the word, “planet”. According to these scientists, a planet must have three
characteristics:
a) It must orbit a Star (Sun)
b) It must have enough mass for its self-gravity to form it into a spherical shape
c) It must have “cleared” nearby objects away from its orbital region by its gravitational force (either by pulling
them in or slinging them away)
As a result of this new definition, Pluto was reclassified from “planet” to “dwarf planet” along with four other large
spherical objects, including Ceres. Currently, scientists are studying hundreds of other objects on the outer edges of our
Solar System, some of which may one day be identified as dwarf planets.
Your Task: Study the twelve cards (Object A – Object L), classify each as a “planet” or a “dwarf planet”, and identify the
eight planets by name given the information on the cards.
Guiding Question: WHICH CARDS REPRESENT EACH OF THE EIGHT PLANETS OF OUR SOLAR SYSTEM?
Materials:
- 12 Cards with information about each object (Object A – Object L)
Knowledge
- Textbook
- Prior
Safety Precautions: None
Getting Started:
In order to identify the planets among your cards, you must first classify each card as a “planet” or a “dwarf planet”.
- What are the characteristics of a planet?
- Which objects don’t fit these characteristics?
Once you have identified which cards represent planets, use your knowledge of the planets to decide which card
represents which planet.
- In what order do the planets orbit the Sun?
- How are the eight planets classified into groups?
- What patterns exist with the orbits of the planets based on their location relative to the Sun?
- What characteristics of individual planets are you already familiar with?
Identifying the Planets Argument Board
QUESTION: WHICH CARDS REPRESENT EACH OF THE EIGHT PLANETS OF OUR SOLAR SYSTEM?
CLAIM: Fill in the chart below to state which objects represent each planet.
EVIDENCE: Fill in the chart below to provide evidence to support each claim.
PLANETS
CLAIM
Mercury
Object _____
Venus
Object _____
Earth
Object _____
Mars
Object _____
Jupiter
Object _____
Saturn
Object _____
Uranus
Object _____
Neptune
Object _____
DWARF PLANETS
Ceres
Pluto
Makemake
Eris
Object _____
Object _____
Object _____
Object _____
EVIDENCE