8        NOT
SCIENCE
    Quarter 2 – Module 5
Comets, Meteors and Asteroids
Science – Grade 8
Alternative Delivery Mode
Quarter 2 – Module 5: Comets, Meteors, and Asteroids
First Edition, 2020
         Republic Act 8293, section 176 states that: No copyright shall subsist in any work
of the Government of the Philippines. However, prior approval of the government agency or
office wherein the work is created shall be necessary for the exploitation of such work for a
profit. Such agency or office may, among other things, impose as a condition the payment of
royalties.
        Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names,
trademarks, etc.) included in this book are owned by their respective copyright holders.
Every effort has been exerted to locate and seek permission to use these materials from
their respective copyright owners. The publisher and authors do not represent nor claim
ownership over them.
Published by the Department of Education – Division of Gingoog City
Division Superintendent: Jesnar Dems S. Torres, Ph.D, CESO VI
                             Development Team of the Module
Writer(s):                 Liezel S. Piquero
Reviewer(s):               Nilda U. Villegas, EPS – Science
                           Florida D. Arias, Ph.D, PSDS
Illustrator(s):            Jay Michael A. Calipusan, PDO II
Layout Artist:             Liezel S. Piquero
 Evaluator:                 Ma. Cynthia E. Herodico
Management Team
         Chairperson:      Jesnar Dems S. Torres, Ph.D, CESO VI
                           Schools Division Superintendent
         Co-Chairperson:   Conniebel C. Nistal, Ph.D
                           Assistant Schools Division Superintendent
                           Pablito B. Altubar, CID Chief
         Members:          Nilda U. Villegas, EPS – Science
                           Himaya B. Sinatao, LRMS Manager
                           Jay Michael A. Calipusan, PDO II
                           Mercy M. Caharian, Librarian II
Printed in the Philippines by
Department of Education – Division of Gingoog City
Office Address:         Brgy. 23, National Highway, Gingoog City
Telefax:          088 328 0108/ 088 328 0118
E-mail Address:   gingoog.city@deped.gov.ph
                      Science
              Quarter 2 - Module 5
              Comets, Meteors, and
                   Asteroids
This page is intentionally blank
                                                   Table of Contents
What This Module is About ........................................................................................................ i
What I Need to Know .................................................................................................................. i
How to Learn from this Module .................................................................................................. ii
Icons of this Module .................................................................................................................. ii
What I know ...............................................................................................................................iii
Lesson 1:
Characteristics of Comets, Meteors, and Asteroids
      What’s In: Activity 1: Recall Who I Am .......................................................................... 1
           What I Need to Know ..................................................................................................... 1
           What’s New: Activity 2 : Draw Me.................................................................................. 2
                               Activity 3: My Uniqueness ........................................................................ 2
                               Activity 4: I am Me .................................................................................... 3
           What Is It ........................................................................................................................ 3
What’s More: Activity 5: Our Difference and Similarities........................................................... 7
           What I have Learned: Activity 6: My Characteristics ..................................................... 8
           What I can Do: Activity 7: Ask and Act .......................................................................... 9
Summary ................................................................................................................................... 9
Assessment: (Post-Test)....................................................................................................... 10
Key to Answers ...................................................................................................................... 11
References .............................................................................................................................. 13
This page is intentionally blank
What This Module is About
         Advancement in space technology allowing scientists coming from different fields
such as physics, chemistry, biology, and geology to a band on studying Near-Earth Objects
(NEO) such as comets and asteroids. Using the more powerful telescopes and space
probes in studying comets and asteroids provides more clues about our solar system begun.
For more than three years, several amateur and professional astronomers successfully
discovered multiple NEO’s that are closer to Earth, the most current asteroid is Asteroid
2012 DA14. The said asteroid made enough distance to Earth as it orbited the Sun last
February 16, 2012, Philippine Time). On the same day, as asteroid step into Earth’s
atmosphere and blew up over Lake Chebarkul in Russia damaging about 1,000 people in
the process. These two incidents resulted in superstitions that have no scientific basis,
worries, and different prophecies by different cultures. But do these things have a scientific
basis?
   Your module will give you an experience outside the earth, giving you a closer look at the
different celestial objects like asteroids, meteors, and comets.
               What I Need to Know?
After going through this module you should be able to:
   1. Compare and contrast comets, asteroids, and meteors.
   2. Draw how impact craters are formed when a meteor or asteroid hits Earth.
   3. Value the importance and occurrence of comets, meteors, and asteroids.
                                               i
How to Learn from this Module
To achieve the objectives cited above, you are to do the following:
   •   Take your time to read the lessons carefully.
   •   Follow the directions and/or instructions in the activities and exercises diligently.
   •   Answer all the given tests and exercises.
Icons of this Module
                             What I Need to          This part contains learning objectives that
                             Know                    are set for you to learn as you go along the
                                                     module.
                             What I know             This is an assessment as to your level of
                                                     knowledge of the subject matter at hand,
                                                     meant specifically to gauge prior related
                                                     knowledge
                                                     This part connects the previous lesson with
                             What’s In               that
                                                     of the current one.
                             What’s New              An introduction to the new lesson through
                                                     various activities, before it will be presented
                                                     to you
                             What is It              These are discussions of the activities as a
                                                     way to deepen your discovery and under-
                                                     standing of the concept.
                             What’s More             These are follow-up activities that are in-
                                                     tended for you to practice further to
                                                     master the competencies.
                             What I Have             Activities designed to process what you
                             Learned                 have learned from the lesson
                             What I can do           These are tasks that are designed to show-
                                                     case your skills and knowledge gained, and
                                                     applied to real-life concerns and situations.
                                                ii
                What I Know (Pre-test)
Direction: For each item, encircle the letter of the correct answer.
1. The primary chemical constituent of comets is
        A. water                                 C. methane
        B. nitrogen                              D. carbon dioxide
2. A meteor shower occurs when
        A. a meteor is about to get married
        B. the earth passes through the asteroid belt
        C. the head of a comet hits the earth’s atmosphere
        D. the earth passes through a swarm of dust particles in space, the remnants of a
        comet, once a year
3. A meteorite is:
        A. a rock from space that strikes the ground
        B. a piece of rock passing through the earth’s atmosphere
        C. the trail left by a piece rock as it passes through the earth’s atmosphere
        D. all of the above
4. Most of the asteroids orbit the sun in a belt between the orbits of
        A. Venus and Mars                        C. Mars and Jupiter
        B. Mars and Earth                        D. Jupiter and Saturn
5. The asteroids are
        A. miniature planets                     C. pockets of gas in the solar system
        B. satellites of planets                 D. planets orbiting the stars other than the sun
6. Comet tails are the result of
        A. interplanetary material streaming into the comet
        B. melting and evaporation of ice from the comet core
        C. dust collected by the comet as it moves in its orbit
        D. solar wind blowing more gases from the central comet core
7. Why are meteorites and comets important in studying the origin of the solar system?
        A. They have recently formed themselves.
        B. They are recently produced fragments of planets.
        C. They represent the material that formed the planets.
        D. None of the above
8. The orbits of most comets, which we see in the inner solar system
        A. are nearly circular                   C. never come closer to the sun
        B. are highly elliptical                 D. are only slightly inclined to the earth’s orbit
9. Most meteoroids are formed when
        A. comets melted                         C. asteroids exploded or collided
        B. volcanoes erupted                     D. satellites exploded or collided
10. Meteors are
        A. falling stars
        B. signals from the other worlds
        C. solar wind particles captured by the earth’s magnetic field
        D. luminous trails left by small extraterrestrial particles rapidly passing
                                                 iii
   Lesson
                        Characteristics of Comets,
      1                      Meteors, and Asteroids
                    What’s In
Activity 1: Recall who I am.
Directions: From your elementary science, describe the following members of the solar
system in your own words. Write your answers on your activity notebook.
1. Comets - _______________________________________________________________
             ______________________________________________________________
2. Meteors - _______________________________________________________________
             _______________________________________________________________
3. Asteroids - ______________________________________________________________
               ______________________________________________________________
               What I Need to Know
Objective: After doing all the activities, the students will be able to compare and contrast
comets, meteors, and asteroids.
                                               1
                 What’s New
Activity 2: Draw Me
Directions: Describe and draw the object. Copy and answer the activity on your activity
notebook.
           Comets                           Meteor               Asteroid
Describe                        Describe                         Describe
Draw the object                 Draw the object                  Draw the object
Activity 3: My Uniqueness
Directions: Describe the object by giving the meaning of each letter of the word. The first
letter of each word is done for you. Copy and answer on your activity notebook.
C - aptivating                  M - agnificient                  A - mazing
O                               E                                S
M                               T                                T
E                               E                                E
T                               O                                R
                                R                                O
                                                                 I
                                                                 D
                                               2
Activity 4: I am Me
Direction: Arrange the characteristics that correspond to each of the objects. Copy and write
your answer on your activity notebook.
Kuiper belt and Oort cloud                        Excluding the tail about the size of the
                                                  mountain
Between the orbits of Mars and Jupiter
                                                  Typically less than 1 km; some are more
Comets and Asteroids                              than 300 km in diameter
Smaller than comets or asteroids                  Ice, dust, small rocky particles
Rock                                              Rock or dust
         Feature              Comets                    Meteors                  Asteroids
Origin
Size
Composition
               What is it?
Comets
    Ever since people know already about comets. You may ask your grandparents about
comets, and they might tell you some superstitions about comets bring bad luck! Why?
Because there are people who believed that comets were bad spirits that look like the
appearance of a woman with a head and its long hair behind. To some ancestors, this was
an old-time sign of mourning. To other people, the appearance of a comet as a sword, a sign
of war, death, and famine.
            Figure 1. Images of a meteor
(www.space.com)
                                              3
         A characteristic of a comet is a fuzzy, luminous big dirty snowball composed of rock
dust wrapped around a big ball of ice. This charming sight in the sky is moving very slowly
but remain in our sight for weeks before disappearing out of view. A comet enters a huge
elliptical orbit. Every time the comet travels closer to the sun, it may lose some of its
material. However, when it comes back to the place part of the solar system, it slowly
appears smaller and gloomy until it disappears completely. In some events, the
characteristic of a comet may have a solid and rocky core for it to continue traveling around
its orbit as a dark barren asteroid.
         Comets do not give energy and light therefore, it is not visible. But as it travels closer
to the sun, the comet becomes clear because the heat of the sun melts the ice of the comet
and turns it to gas. This gas becomes the coma, which envelopes and hides the nucleus from our
view. One part of the comet is the so-called head. It is composed of a nucleus and coma. It
becomes bigger as more gas and dust are released from the coma. The solar wind blows
more and more gas from the coma causing it to form a tail, which in some comets, can reach
up to 150 million kilometers in length!
           Figure 2 shows the parts of a comet (www.solarsystem.nasa.gov.earth)
         Most comets are thought to originate from a huge cloud called the Oort cloud, which
is too far away for astronomers to see.
                     Figure 3. Halley’s Comet (www.solarsystem.nasa.gov.earth)
                                                4
       One of the most unique short-period comets is the Halley’s Comet because it has an
average orbital period of fewer than 200 years, Halley’s Comet appears once every 76
years. Because most other comets are long-period comets that can take up to a million
years to orbit the sun. Hale-Bopp comet is an example of long-period comets.
       Based on the study there is no clear evidence showing that a comet has ever hit into
the earth. But some scientists claimed that comet is one of the main possible reasons that
explain the extinction of dinosaurs million years ago. They hypothesized that a large comet
entered into the earth and caused a massive distraction like earthquakes, tsunami which
later on caused the changes in the temperature and climate and eventually wiped out
dinosaurs.
Meteors
         You can ask your parents and other family members about a falling star? What is a
falling star? Can you catch it? Will it fit in your pocket?
         Another known celestial object in the solar system is the meteors. They are dust and
ice from the pathway of comets. Meteors are stone-like but made up of several minerals and
rich in silicon and oxygen, “iron”, consisting mainly of iron and nickel, or “stony-iron”, a
combination of the two.
         When meteors travel through the layer of the earth's atmosphere friction caused
them to heats up, and then the meteor’s surface starts to warm up and flare. That's the time
the heat and high speed combine to vaporize the meteor usually high above Earth’s surface.
Many people considered meteor as a falling star or shooting star. It will happen when a
meteoroid is passing through the Earth’s atmosphere and heats up in the process.
         You can differentiate an asteroid and a meteor through their characteristics, an
asteroid is a small rocky object that travels around the Sun. A meteor will occur when a tiny
piece of an asteroid or comet, which is known as a meteoroid, flare-up upon traveling Earth’s
atmosphere.
  Figure 2. Meteors (www.accuweather.com)
       The observable light emitted by a meteor may take on various colors, depending on
the chemical composition of the meteoroid, and the speed of its movement through the
atmosphere.
       Color of meteors are depending on the relevant influence of the metallic content of
the meteoroid and the super-heated air plasma, which its track produces:
           Orange-yellow (sodium)                            Violet (calcium)
           Yellow (iron)                                     Red (atmospheric nitrogen
           Blue-green (magnesium)                               and oxygen)
                                            5
MORE INTERESTING METEOR FACTS
   There are millions of meteors in the Earth’s atmosphere every day.
   Meteors can become visible as high as 120 kilometers above Earth.
   Meteors can give off various colors when they burn which is associated with their
    composition.
   Meteors that burn brighter than usual are called fireballs.
   Most fireballs go unseen because they occur over the ocean or during daylight hours.
   Meteors usually burn up in the Earth’s atmosphere.
   If a meteor produces a sound, called a sonic boom, it is typically heard seconds after the
    meteor becomes visible.
   Although meteors have existed since ancient times, they were not believed to be from
    our solar system until 1833.
   Usually, meteors are the size of pebbles and no larger than a baseball.
Asteroids
        Another fascinating object in the solar system are the asteroids, they simply rocky or
metallic objects orbiting the sun in the same way that planets orbit. However, asteroids are
hard to see because they are reflecting little light and they are always moving. No asteroids
have an atmosphere.
        Asteroids come in all sizes and shapes. Some asteroids that are tiny as pebbles and
some are as big as mountains. And because they are smaller than planets, they are often
called minor planets or planetoids. Ceres is the largest of the asteroids. It is about 930
kilometers in diameter. Can you imagine how huge that is? Like any other big rock, they can
be potato-shaped, papaya-shaped, or have strange shapes!
       Figure 1.Asteroids (www.space.com)
        There many asteroids orbiting the sun in a region between Mars and Jupiter. This
area is called the asteroid belt. They are following a slightly elliptical path as they orbit the
sun in the same direction as the planets.
        A larger object such as a planet could be pulled an asteroid out of orbit. And once an
asteroid is captured by the gravitational pull of a planet, it may become a satellite of that
planet. Many astronomers believe that the two satellites of Mars, Phobos, and Deimos, are
captured asteroids.
                                               6
        If it is not because of the giant planet Jupiter that pulls the asteroids outward, large
asteroids would constantly be hitting Mercury, Venus, Mars, and Earth. I hope you still
remember those inner planets that you learned from your previous module. You already
learned that the belt is closer to Jupiter than it is to the sun, Jupiter exerts more gravitational
pull on the asteroids than the sun. Resulting in the asteroids to keep in orbit away from the
inner planets.
               What’s More
Activity 5: Our Differences and Similarities
Directions: Copy and answer on your activity notebook.
Objective: At the end of the activity you must be able to compare and contrast the
           characteristics of comets, meteors, and asteroids.
Materials: paper and pen
                   comet
                                                                         asteroids
                                            common
                                          characteristics
                meteors
                                   Venn Diagram (www.lucidchart.com)
                                                 7
              What I Have Learned
Activity 6: My Characteristics
Direction: Answer on your activity notebook.
   A. After exploring the amazing asteroids, comets, and meteors, test yourself if you can
      differentiate the three: comets, meteors, and asteroids
   B. Given below are some characteristics of comets, meteors, and asteroids. On the
      space provided, write
              A. if it refers to comets
              B. if it refers to meteors
              C. if it refers to asteroids
              D. both comets and meteors
              E. if it refers to both meteors and asteroids
              F. if it refers to both asteroids and comets
              G. if it refers to all (comets, meteors, and asteroid)
Characteristics:
      ___1. Progress across the sky very slowly
      ___2. Known as falling stars or shooting stars
      ___3. Remnants of the formation of the solar system
      ___4. They glow as they enter the earth’s atmosphere
      ___5. Reflect sunlight
      ___6. Rocky composition
      ___7. Orbit the sun in highly elliptical orbits s
      ___8. Minor planets
      ___9. Mostly found between Mars and Jupiter
      ___10. Can reach 150 million km in length
      ___11. Most have slightly elliptical orbits
      ___12. The result from the collision of asteroids
      ___13. Streak across the sky very fast
      ___14. Come in all sizes and shapes
      ___15. Icy object
                                               8
               What I Can Do
Activity 7: Ask and Act
Objectives:
       After performing this activity, the students must be able to:
   1. Provide sound, scientific evidence to support one’s stand about superstitions
       on comets, asteroids, and meteors; and
   2. Formulate doable actions to address superstitions on comets, asteroids, and
       meteors.
Materials Needed
       Pen
       Paper (for taking notes)
Procedure:
   1. Research about superstitions related to comet and asteroid in the library and by
       interviewing your parents or elderly members of the family.
   2. Choose at least 3 superstitions.
   3. Discuss each superstition with your family to answer the question: Do superstitions
       about comets and asteroids have a scientific basis? Why or Why not?
   4. List down as much scientific evidence to support the group’s answer to the question.
Data:
   1. Do superstitions about comets and an asteroids have scientific basis? Why?
_________________________________________________________________________
_________________________________________________________________________
   2. What scientific facts/evidence to support the group’s answer?
_________________________________________________________________________
_________________________________________________________________________
   3. Proposed actions to promote a more scientific understanding of comets, asteroids,
      and meteors.
_________________________________________________________________________
_________________________________________________________________________
Summary
         Comets, Asteroids, and Meteors are also considered as celestial objects that orbit
around the sun. They come in different sizes and shapes. Asteroids follow a slightly elliptical
orbit, a comet is a fuzzy, luminous big dirty snowball composed of rock dust wrapped around
a big ball of ice. Comet has three parts the nucleus, head, and tail. Meteor is a piece of a
stony or metallic object which all travels in space and all has a great impact on the earth
when
reaches                         the                      earth’s                     surface.
                                              9
               Assessment (Post-Test)
Direction: For each item, encircle the letter of the correct answer.
1. Most of the asteroids orbit the sun in a belt between the orbits of
        A. Venus and Mars                        C. Jupiter and Saturn
        B. Mars and Earth                        D. Mars and Jupiter
2. The primary chemical constituent of comets is
        A. water                                 C. methane
        B. nitrogen                              D. carbon dioxide
3. A meteorite is
        A. a rock from space that strikes the ground
        B. a piece of rock passing through the earth’s atmosphere
        C. the trail left by a rock as it passes through the earth’s atmosphere
        D. all of the above
4. A meteor shower occurs when
        A. a meteor is about to get married
        B. the earth passes through the asteroid belt
        C. the head of a comet hits the earth’s atmosphere
        D. the earth passes through a swarm of dust particles in space, the remnants of a
        comet, once a year
5. The asteroids are
        A. miniature planets                     C. pockets of gas in the solar system
        B. satellites of planets                 D. planets orbiting the stars other than the sun
6. Why are meteorites and comets important in studying the origin of the solar system?
        A. They have recently formed themselves.
        B. They are recently produced fragments of planets.
        C. They represent the material that formed the planets.
        D. none of the above
7. Comet tails are the result of
        A. interplanetary material streaming into the comet
        B. melting and evaporation of ice from the comet core
        C. dust collected by the comet as it moves in its orbit
        D. solar wind blowing more gases from the central comet core
8. Meteors are
        A. falling stars
        B. signals from the other worlds
        C. solar wind particles captured by the earth’s magnetic field
        D. luminous trails left by small extraterrestrial particles rapidly passing through the air
9. The orbits of most comets, which we see in the inner solar system
        A. are nearly circular                   C. never come closer to the sun
        B. are highly elliptical                 D. are only slightly inclined to the earth’s orbit
10. The first satellite to discover a comet was/were
        A. Mariner 2                             C. Hubble Telescopes
        B. Vikings 1 and 2                       D. Infrared Astronomical Satellite
                                                10
Key to Answers
             11
     15
12
References
Asteroids and Comets. Retrieved July 28, 2004, http://www.uen.org/utahlink/activities
Asteroids. Retrieved September 2, 2004, http://starchild.gsfc.nasa.gov
Do Superstitions about comets, asteroids, and meteors have a scientific basis? First Edition
   2013 Department of Education-Instructional Materials Council Secretariat (DepEd-
   IMCHS) Pasay City. Page 165-166
Ocampo, Pia C., et.al., Science – Grade 8 Learner’s Material Unit 2 Module 3, Activity 3,
   Page 165-167
Project EASE – First-year Science Learner’s Module 17, Other Minor Members of the Solar
    System.2010 Edition. Department of Education. DepEd Complex, Meralco Avenue,
    Pasig Avenue
Space Object Differences from http://www.sciencekids.co.nz
https://www.solarsystem.nasa.gov.earth
www.scienceclarified.com/scitech/Comets-and-Asteroids/How-Asteroids-and-Comets.html
                                             13
For inquiries and feedback, please write or call:
Department of Education – Bureau of Learning Resources (DepEd-BLR)
Department of Education – Division of Gingoog City
Office Address:   Brgy. 23, National Highway, Gingoog City
Telefax:          088 328 0108/ 088 328 0118
E-mail Address:   gingoog.city@deped.gov.ph