Comet Myths, Facts and Legends
Teacher Page: Lesson Plan
[ Overview
] [ Author
] [ Lesson
Plan ] [ National
Standards ] [ Science
Background ] [ Grab
Bag ] [ Computer
Needs ] [ Back
to the Lesson ] [ Index
]
Index:
Goal/Purpose
Desired Learning Outcomes
Prerequisites
New Vocabulary
General Misconceptions
Preparation Time
Execution Time by Module
Physical Layout of Room
Materials
Procedure / Directions
Evaluation / Assessment
Solutions
Follow-up Activities / Interdisciplinary Connections
One-Computer Classroom
Classrooms Without Computers
Home Schooler
Goal/Purpose:
The purpose of this lesson is for students to explore some facts,
myths, and legends linked to the appearance of comets throughout history.
Desired Learning Outcomes:
- Identify one fact, legend and/or myth associated with comets.
- Identify a property of comets and explain how that property makes
comets visible.
- Describe the path of a comet and explain how this affects its reappearance.
Prerequisites:
Before attempting to complete this lesson, the student should:
- Understand that the solar system consists of planets, moons, asteroids,
comets, and the Sun.
- Understand the difference between a fact, a legend and a myth.
New Vocabulary:
- Asteroid
- A small solar system object composed mostly of rock. Many of these
objects orbit the Sun between Mars and Jupiter. Their size can range
anywhere from 10 meters in diameter to less than 1,000 kilometers.
- Coma
- The cloud that forms around a comet's nucleus. This cloud is made
by solar wind striking the surface of the nucleus, causing a mixture
of gas and dust to form around it.
- Comet
- A small solar system object consisting of ice and other compounds.
A comet will form a coma and sometimes a visible tail whenever it
orbits close to the Sun.
- Dust Tail
- This type of comet tail forms when the solar wind separates dust
from the coma, pushing it outward away from the Sun in a slightly
curved path.
- Gas-Ion Tail
- This type of comet tail forms when the solar wind separates gases
from the coma, pushing them outward away from the Sun in a straight
path.
- Inner Solar System
- The path of the solar system between the Sun and the orbit of Jupiter
- Meteor
- The flash of light that we see in the night sky caused by the friction
of a meteoroid passing through the atmosphere.
- Meteor Shower
- Many and sustained flashes of light that are seen in the night sky
as a result of the Earth passing through the former path of a comet.
The debris released by the comet causes the meteor shower.
- Meteorite
- Any part of a meteoroid that that survives its fall through the
atmosphere and lands on the Earth.
- Meteoroid
- An interplanetary chunk of matter that is smaller than a kilometer
in diameter and most frequently measured in millimeters.
- Naked-eye Visibility
- Being able to see a celestial object, such as a comet, without the
aid of telescopes, binoculars or other astronomical devices.
- Comet Nucleus
- The solid rocky part of a comet.
- Orbit
- The path followed by one celestial object around another celestial
object, such as Earth’s path around the Sun or the Moon’s
path around Earth.
- Period
- The time needed for one complete trip or cycle. For example, the
period for the Earth to travel around the Sun is 365 days.
- Solar Wind
- A stream of charged particles ejected from the surface of a star.
General Misconceptions:
Misconception: Comets
are not a part of the solar system.
Reality: Comets are part of the solar system.
They are believed to originate from one of two locations within the
solar system: the Kuiper belt and the Oort Cloud.
Misconception: Comets
are similar to asteroids.
Reality: Comets and asteroids have a very
different make-up. Asteroids are composed of rocky and metallic material
while comets are composed of water ice, dust, and carbon- and silicon-based
compounds.
Misconception: All
comets look the same and don’t change their appearance.
Reality: Comets have a coma and one, two,
or three tails when near the Sun, and no coma or tail when far way from
the Sun.
Misconception: Pluto
is the most-distant and last object in the solar system.
Reality: Beyond Pluto’s orbit is
a group of icy objects known as the Kuiper belt, from which short-period
comets emerge. Further still is a sphere of icy bodies, called the Oort
Cloud, from which long-period comets emerge. Short-period comets visit
the inner solar system frequently while the long-period comets visit
infrequently.
Misconception: There
is empty space between the planets.
Reality: There is gas and dust, also known
as the interplanetary medium, between the planets. Comets are responsible
for depositing some of the gas and dust found in the inner solar system.
Preparation
Time:
- Provide time to download computer software to support the lesson.
- Allow time to preview the activity and to read the science background
pages.
Execution Time:
The amount of time needed to complete this activity will vary depending
on the length of available teaching time, the ratio of computers to
students in the class and how/what you have your students do. The navigation
through the activity is quite simple but you might want to use an overhead,
an LCD, or a TV monitor to show the activity to the class ahead of time.
The following is an estimated time:
- "Comet Facts, Myths, and Legends" should take about 20 minutes to read.
Physical Layout of
Room:
Teachers may decide whether students will work in small groups of two
or three, or individually. To maximize learning, no more than three
students should share a computer. Adaptations can be made to accommodate
classrooms with a single computer with Internet access. These might
include using an overhead projector with an LCD to project the computer
image onto a screen, or hooking up a computer to a television monitor.
You can also do "Comet Facts, Myths, and Legends" off-line. Different
software programs provide off-line access to the Internet. The programs
allow you to save Web pages to your local hard drive. Using your Web
browser, you can open the Web pages locally and experience the lesson
as if you were on the Internet. Using this option, however, will deny
students access to the rest of the pages available on the World Wide
Web.
Materials:
This activity requires a computer with a color monitor and Internet
connection. The Web browser must be capable of running Netscape's Navigator
3.0 (or better) or Internet Explorer 4.0 (or better). For additional
information, read the Computer Needs section.
Procedure / Directions:
This is a self-directed computer activity. Students may work independently
or in small groups to complete the activity.
Suggested Engagement Activities:
- Project images of comets, which can be found at the Space Telescope
Science Institute's Web site, http://www.stsci.edu,
onto a screen or television monitor. In a class discussion, ask students
to describe what they already know about comets and planets, and what
they can learn from the images.
- Organize an informal debate or discussion on the topic, Comet Collisions
with Earth: Fact or Myth?
Evaluation / Assessment:
Share the learning outcomes with your students ahead of time. Following
the activity, ask students to answer one or more of the following questions,
which are derived from the outcomes and based on the reading:
- Identify a fact associated with comets.
- Identify a legend associated with comets.
- Identify a myth associated with comets.
- Comets are small solar system objects, yet ancient cultures knew
about comets. Identify one property of comets that explains why humanity
has known of comets for so long.
- Describe the path of a comet and explain how this affects its reappearance.
- Short-period comets tend to originate from the Kuiper belt
a region beyond the orbit of Neptune and similar in shape to the Asteroid
belt. Long-period comets tend to originate from the Oort Cloud
a spherical region well beyond the orbits of Neptune and Pluto. Based
on the reading, explain where each of the following comets is likely
to have originated: Hale-Bopp, Swift-Tuttle, Hyakutake, and Halley’s
comet. Explain your choices.
Solutions:
- Identify a fact associated with comets.
Some possible answers are included here but there are other correct
answers. Comets travel far beyond the orbit of the Moon. Comets move
in elliptical orbits around the Sun. Comets return to the inner solar
system at predictable times. Edmund Halley correctly predicted the return
of the comet named for him. Comets leave a trail of debris behind them.
For a long time afterwards, whenever the Earth passes through the left-behind
trails, the debris strikes our atmosphere and causes meteor showers.
- Identify a legend associated with comets.
Some people in ancient times thought that a comet was a curse. To save
himself from the "curse of the comet," Emperor Nero of Rome had all
possible successors to his throne executed.
The famous Bayeux Tapestry, which commemorates the Norman Conquest
of England in 1066, depicts an image of Halley's comet bright in the
sky before the Battle of Hastings. Some people thought this meant that
King Harold would lose his throne to William, the Duke of Normandy.
He did.
- Identify a myth associated with comets.
Most astronomers in the 1500's and early 1600's thought that a comet
appeared once and was never seen again. They believed that a comet approached
the Sun in a straight line, spun around it, and then disappeared into
space in a straight path. Another myth claims that the gas from a comet
tail is poisonous and can affect people on Earth if its path crosses
the planet.
- Comets are small solar system objects, yet ancient
cultures knew about comets. Identify one property of comets that explains
why humanity has known of comets for so long.
Students will probably identify the tail as the primary feature that
makes comets visible. Comets have bright tails when near the Sun
this makes them visible. Comets are composed of ice and dust, which
changes to gas when their elliptical orbits bring them close to the
Sun. The gas creates a coma and flowing tail(s).
- Describe the path of a comet and explain how this affects
its reappearance.
Comets move in orbits around the Sun. Since the path is a complete
oval, comets return to the inner solar system at predictable times.
- Short-period comets tend to originate from the Kuiper
belt a region beyond the orbit of Neptune similar in shape to
the Asteroid belt. Long-period comets tend to originate from the Oort
Cloud a spherical region well beyond the orbits of Neptune and
Pluto. Based on the reading, explain where each of the following comets
is likely to have originated: Hale-Bopp, Swift-Tuttle, Hyakutake and
Halley’s Comet. Explain your choices.
Comets from the Kuiper belt tend to have short periods - like Halley's
Comet, which reappears every 76 years or comet Swift-Tuttle, which reappears
every 120 years. Comets from the Oort Cloud tend to have long periods,
like Comet Hale-Bopp with its 2,400-year period or Hyakutake, which
will not appear again for another 14,000 years.
Follow-up Activities /
Interdisciplinary Connections:
You can find other images of comets and planets at the Space Telescope
Science Institute. These images could be shown directly to the class
using an overhead projector, an LCD, or a TV monitor. Paper-copy versions
of images taken by the Hubble Space Telescope and other NASA missions
also are available at your closest NASA Educator Resource Center.
Connections to other disciplines can be used to broaden classroom discussion
of Comets Facts, Myths, and Legends.
Biology: Some scientists think that
a comet or asteroid collided with the Earth and killed the dinosaurs
millions of years ago. Research and discuss this idea.
English: Ask students to write a
poem or a story about a comet.
Social Studies: Ask students to
research the relevance of comets in different cultures. Have them
search for references to comets and the myths that might be associated
with the appearance of a particular comet.
Art: Have students study art that
includes comets and/or create a picture showing what it might look
like if a very bright comet were in the sky around their school.
One-Computer Classroom:
It is recommended that teachers project the images from the computer
onto a classroom screen using an overhead, LCD or television screen.
To facilitate a more organized and predictable large-group presentation
and avoid last-minute glitches, consider bookmarking the activity (such
as one of the pages you wish to use) and downloading it onto your hard
disk. This will eliminate the inconvenience of unexpectedly losing your
connection to the Internet.
Classrooms without
Computers:
Here are some suggestions:
- If you have access to a computer with World Wide Web capabilities
at home or in the school library, you may print selected parts of
the activity as paper copies or transparencies.
- If your school has one or more computers located outside your classroom,
students may experience the activity individually or in small groups
as a learning station.
- Some students might have computers at home with access to the Internet.
If that's the case, you might consider assigning Comets Facts, Myths,
and Legends as homework or extra credit.
- NASA offers FREE comet and solar system-related lithographs and
posters, which are available at your closest NASA Educator Resource
Center. They can be used as teaching tools in the classroom.
Home Schooler:
This lesson is easily followed without additional teacher support if
the prerequisites are met. Parents can preview the lesson and examine
the teacher pages ahead of time. A wealth of information can be found
at HubbleSite, the Hubble Space
Telescope's Web site at the Space Telescope Science Institute. Here
you can find background information on the telescope, pictures and news
releases of past and present stories, education activities, and other
science resources.
More information for the home-schooled can be found at:
Send your comments about this page to: amazing-space@stsci.edu |