The Origin of the Element
Name ______________________________
Directions:
1. Download the document to your desktop. Read the Introduction, answer the questions in the right
hand column labeled “Predict”.
2. Watch the video “The Origin of the Elements”
https://scetv.pbslearningmedia.org/resource/phy03.sci.phys.matter.origin/the-origin-of-theelements/#.WamisNN95p8
3. Decide what are keywords and underline or highlight them in each sentence.
4. Look at the keywords and write a summary sentence for each paragraph. In right hand column, write
the sentence. Answer the questions and then upload your document back to Google Classroom.
PREDICT:
What is this reading going to be about
Introduction:
In this video from NASA, learn about the history of defining a
today and what are you going to be
planet, and examine how classification changes based on new
doing? How do you know, give 3
knowledge. Our understanding of the solar system has evolved
reasons.
since the ancient Greeks, who first used the word planets to
distinguish the objects that moved against the backdrop of stars in 1.
the night sky. The discovery of Pluto and Eris rekindled the debate
over what a planet is, and in 2006, the International Astronomical
2.
Union (IAU) issued definitions for planets and dwarf planets.
However, the debate continues among scientists all over the world. 3.
Background Essay:


Summary Sentences
Until relatively recently, there were no official standards for how to Paragraph 1:
classify the various objects in our solar system that orbit the Sun. In
2006, the International Astronomical Union (IAU) released formal
definitions that designated three classes of objects in the solar
system: planets, dwarf planets, and small solar system bodies.
In essence, the IAU’s definitions state that:
Paragraph 2:
*A planet is a celestial body that is in orbit around the Sun;
assumes a nearly round shape due to its own gravity; and has
cleared the neighborhood around its orbit.
*A dwarf planet is a celestial body that is in orbit around the Sun;
assumes a nearly round shape due to its own gravity;.
and has not cleared the neighborhood around its orbit.
Despite having the word “planet” in the name, a dwarf planet is a
distinct class of object and not a type of planet.
Small solar system bodies are all other objects that orbit the Sun,
Paragraph 3:
such as asteroids and comets, and are not satellites (i.e., they do
not orbit another planet, dwarf planet, or solar system body).
According to the IAU, our solar system contains eight planets
(Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and
Neptune) and five recognized dwarf planets (Ceres, Pluto,
Haumea, Makemake, and Eris, as of 2014). There are a number of
other known objects that may one day be classified as dwarf
planets and there may be potentially hundreds of yet undiscovered
Paragraph 4:
dwarf planets.
However, the IAU definitions remain controversial. Some scientists
object to the unclear wording of the definitions, which leave room
for interpretation. For example, there is no clear boundary for how
round an object needs to be to be considered “nearly round.” And
what does “clearing the neighborhood around its orbit” really
mean?
Paragraph 5:
However, the IAU definitions remain controversial. Some scientists
object to the unclear wording of the definitions, which leave room
for interpretation. For example, there is no clear boundary for how
round an object needs to be to be considered “nearly round.” And
what does “clearing the neighborhood around its orbit” really
mean?
Paragraph 6:
However, the IAU definitions remain controversial. Some scientists
object to the unclear wording of the definitions, which leave room
for interpretation. For example, there is no clear boundary for how
round an object needs to be to be considered “nearly round.” And
what does “clearing the neighborhood around its orbit” really
mean?
Paragraph 7:
Questions:
1.
How many planets were listed in the solar system at the middle of the 19th century? Why did the
number of planets go down to eight by the early 20th century?
2.
How do advances in technology affect our understanding of the solar system?
3.
Why does scientific classification change over time?
4.
What are the three criteria in the IAU definition of a planet? What is the IAU definition of a dwarf
planet?
5.
Why do some astronomers disagree with the IAU definitions?
https://scetv.pbslearningmedia.org/resource/phy03.sci.phys.matter.origin/the-origin-of-theelements/#.WamisNN95p8