Document Sample
D IRECTO RY Powered By Docstoc
					Exploring Ice                                                                                                   MAIN MENU

                                                                                          LIFE IN ICY PL ACES

                         SCIENCE & LITERATURE                                  2

                         CONCEPT OVERVIEW                                      3

                            PRE K– GRADE 2 CONCEPTS                            3

                            GRADE 3– GRADE 5 CONCEPTS                          3

                         LESSON SUMMARY & OBJECTIVES                           4

                         STANDARDS                                             4

                         ESSENTIAL QUESTION                                    5

                         ACTIVITY QUESTION                                     5

                         BACKGROUND                                            6

                         ACT OUT THE SCIENCE                                  10

                         MATERIALS                                            14

                         DEMONSTRATION                                        15

                            PRE K– GRADE 2                                    15
                            GRADE 3– GRADE 5                                  15

                         MAIN ACTIVITY                                        16

                            PREPARATION                                       16

                            TEACHING TIPS                                     16

                            WARM-UP AND PRE-ASSESSMENT                        17

                            PROCEDURES                                        18

                            DISCUSSION AND REFLECTION                         21

                            CURRICULUM CONNECTIONS                            22

                         ASSESSMENT CRITERIA                                  23

                         RESOURCES                                            24


                                                      This lesson develops pre-
                                                      cursor understanding
                                                      about the field of astrobi-
                                                      ology, the study of life in
                                                      the universe and explores
                                                      how ice can harbor life
                                                      and preserve evidence
                                                      of life.
Exploring Ice            LIFE IN ICY PLACES                                                   LESSON 8 DIRECTORY MAIN MENU

                         SCIENCE & LITERATURE
                         Ice plays a significant role in the field of         “Ancient microbes can remain viable
                         astrobiology, the study of life in the universe.     through cryopreservation, becoming
                         With the discovery that life can flourish in
                                                                              dormant and then resuming metabolic
                         extreme environments, such as ice, scientists
                         have expanded their search of where to               activity upon thawing after being
                         look for conditions for life in other places         frozen in glacial ice or permafrost
                         in the Solar System and beyond.
                                                                              for thousands to millions of years.   ”
                                                                                      — Richard Hoover,

                                                                                         Astrobiologist at NASA’s

                                                                                         Marshal Space Flight Center


Exploring Ice            LIFE IN ICY PLACES                                                       LESSON 8 DIRECTORY MAIN MENU

                         CONCEPT OVERVIEW
                         This lesson develops precursor under-             PRE K – 2 CONCEPTS
                         standing about the field of astrobiology,          s   Some forms of life can survive in
                         the study of life in the universe and                 extreme conditions.
                         explores how ice can harbor life and              s   Some forms of life can survive freezing
                         preserve evidence of life.                            cold conditions.
                         Concepts:                                         s   Ice can harbor microbial life and can
                         s Astrobiology
                                                                               preserve signs of life.
                         s   Extremophiles                                 s   Microbial life may exist in other icy
                         s   Microbes                                          places in the Solar System.

                         This Lesson Provides a Concrete                   s   Astrobiology is the study of life in
                         Experience of:                                        the universe.
                         1. How astrobiologists look for evidence
                            of life in icy conditions.                     GRADE 3 – 5 CONCEPTS
                         2. Evidence of effects of freezing temperatures   s   Organisms can survive under extreme
                            on microbial activity.                             environmental conditions such as heat,
                                                                               cold, and radiation.
                         This lesson connects these experiences to
                         conceptual understanding of how some forms        s   The term extremophiles describes life that
                         of life can exist in or near icy conditions.          flourishes in extreme environments.

                                                                           s   Some forms of life can extract energy to
                                                                               stay alive and grow in very cold and icy
                                                                               places on Earth.

                                                                           s   Ice can harbor life in a dormant phase
                                                                               and can preserve evidence of life
                                                                               processes (biomarkers).

                                                                           s   Microbial life may exist in other icy
                                                                               places in the Solar System.

                                                                           s   Astrobiology is the study of life in
                                                                               the universe.

Exploring Ice            LIFE IN ICY PLACES                                                       LESSON 8 DIRECTORY MAIN MENU

                         LESSON SUMMARY & OBJECTIVES                         STANDARDS
                         To survive in extremely cold and icy                BENCHMARKS
                         conditions, living organisms must develop           5A The Living Environment: Diversity of Life
                         effective strategies to extract energy to           GRADES K–2, PAGE 102
                         stay alive and grow.                                s Plants and animals have features that help

                                                                               them live in different environments.
                         By looking at how life copes in very cold
                         conditions, we can learn more about the             5C The Living Environment: Cells
                         fundamentals of what life is.                       GRADES K–2, PAGE 111
                                                                             s Most living things need water, food, and air.
                         Objective 1: Notice that freezing
                                                                             GRADES 3–5, PAGE 111
                         inactivates microbes.
                                                                             s Some living things consist of a single cell.
                         “Spoiling” is caused by the activity of bacteria,
                                                                               Like familiar organisms, they need food,
                         yeasts, and molds that decompose food.
                                                                               water, and air; a way to dispose of waste;
                         We keep food in the refrigerator and
                                                                               and an environment they can live in.
                         the freezer to slow down or stop the
                         decomposing process. When energy-                   5D The Living Environment:
                         extracting activity is inhibited, microbes          Interdependence of Life
                         enter an inactive, or dormant, phase.               GRADES K –2, PAGE 116
                                                                             s Living things are found almost everywhere
                         Objective 2: Notice that ice can preserve             in the world. There are somewhat different
                         evidence of life processes.                           kinds in different places.
                         Glacial ice cores preserve signs of the
                         presence of life and can harbor dormant             NSES
                         phases of microbial life.                           Content Standard C Life Science:
                                                                             The characteristics of organisms
                         Objective 3: Notice that scientists have
             PRINT                                                           GRADES K–4, PAGE 129
                         discovered icy places where life exists.
                                                                             s Organisms have basic needs. For example, ani-
                         Extremophiles are organisms that survive
                                                                               mals need air, water, and food; plants require
                         in extreme conditions. By studying life in
                                                                               air, water, nutrients, and light. Organisms can
                         extremely cold environment, we expand
                                                                               survive only in environments in which their
                         our thinking about the possibility of life
                                                                               needs can be met. The world has many differ-
                         arising in similar conditions in other places
                                                                               ent environments, and distinct environments
                         in the Solar System.
                                                                               support the life of different types of organisms.

                                                                             GRADES 5–8, PAGE 156
                                                                             s All organisms are composed of cells—the

                                                                               fundamental unit of life. Most organisms are
                                                                               single cells; other organisms, including humans,
                                                                               are multicellular.
Exploring Ice            LIFE IN ICY PLACES                                                LESSON 8 DIRECTORY MAIN MENU

                         ESSENTIAL QUESTION                             ACTIVITY QUESTION
                         Under what conditions can life exist           What is the relationship between ice
                         and sustain itself?                            and life?
                         What conditions are necessary for life to      What enables some forms of microbial
                         exist? What are extreme conditions with        life to survive freezing? What strategies do
                         respect to life? What have astrobiologists     extremophiles use to survive in sub-freezing
                         discovered about life in extreme conditions?   conditions? How do we detect the presence
                         How does this affect our understanding         or past-presence of life in extreme cold?
                         about life?                                    How does ice harbor and/or preserve life?


Exploring Ice            LIFE IN ICY PLACES                                                                 LESSON 8 DIRECTORY MAIN MENU

                         What is Astrobiology?                                          Looking for Life in all Extreme Places
                         Astrobiology is the scientific study of the living              Recent research about life in extreme envi-
                         universe: its past, present, and future. It starts             ronments has yielded tremendous rethinking
                         with investigating life on Earth, the only place               about the boundaries of life and the condi-
                         where life is known to exist, and extends into                 tions where life can survive. Within the last
                         the farthest reaches of the cosmos. It ranges                  decades of the twentieth century, scientists
                         in time from the big bang and continues on                     have discovered the presence of microbial
                         into the future.                                               life in unimaginable extremes of ice cold and
                                                                                        fiery heat.
                         Astrobiology draws information from
                         chemistry, geology, astronomy, planetary                       New definitions have emerged about the
                         science, paleontology, oceanography, physics,                  boundaries of life and understandings about
                         biology, mathematics…and emerges with a                        where life can exist. Heat vents breaking
                         unique perspective.                                            through the surface of deep oceans have
                                                                                        been revealed as places where life flourishes.
                         Astrobiology covers a diverse range
                                                                                        The underside of sea ice has been shown
                         of topics that can be categorized under
                                                                                        to harbor life.
                         major questions:
                                                                                        Extreme is in the mind of the beholder.
                         s   Where did life come from?
                                                                                        From our human point of view the roiling
                         s   What is its future?
                                                                                        sulfurous heat vents deep in the ocean and
                         s   Are we alone in the universe?
                                                                                        the frigid layers of ice deep in the Antarctic
                         While these questions have been asked for                      glaciers are extreme. For the forms of life
                         millennia, rapid advances in the sciences and                  that have adapted to those niches, those
                         the ability to travel out into space have set the              conditions are normal. Astrobiologists seek
                         stage for a novel scientific examination. As any
                                                                                        to understand life’s ingenious solutions for
                         such newborn, Astrobiology is growing and                      selecting survival strategies. The findings of
                         maturing rapidly. Breakthroughs and discover-                  the astrobiologists are transforming our
                         ies are routine. But rather than a description                 view of the boundaries and capabilities of
                         of each new research finding, the definition                     life. As we explore the Solar System and
                         of Astrobiology must be that of a whole,                       beyond, we are looking for places, extreme
                         greater than the sum of its parts. It is a                     as they may seem, where microbial life
                         collaborative effort; a new practice that                      might take hold.
                         leverages and transcends traditional scientific
                         discipline boundaries to create an innovation
                         in interdisciplinary communication.
                         Source: NASA Astrobiology Institute

Exploring Ice            LIFE IN ICY PLACES                                                            LESSON 8 DIRECTORY MAIN MENU

                         Richard Hoover, Astrobiologist at NASA’s            Students need to discern the difference
                         Marshal Space Flight Center makes the               between science and pseudoscience. The
                         following three points:                             distinction is not always very clear, particu-
                                                                             larly as recent discoveries in astrobiology
                         s   The microbial extremophiles in the Arctic
                                                                             change our perspectives about the conditions
                             and Antarctic glaciers and permafrost
                                                                             necessary for life.
                             represent analogues for microbes that may
                             someday be found in the permafrost or           Hardy Bacteria Could Survive
                             ice caps of Mars or on other icy bodies         Trip in Space
                             of the Solar System.                            Microbial life forms that exist in extreme
                         s   Ancient microbes can remain viable              environments are called extremophiles.
                             through cryopreservation, becoming
                                                                             Super extremophile, Deinococcus radiodurans
                             dormant and then resuming metabolic
                                                                             was discovered in the 1950s. Scientists experi-
                             activity upon thawing after being frozen
                                                                             menting with radiation to kill bacteria and
                             in glacial ice or permafrost for thousands
                                                                             preserve food for long periods found that
                             to millions of years.
                                                                             something kept growing back after treatment.
                         s   These ancient cryopreserved microbiota
                                                                             Scientists hypothesize that this hardy strain of
                             may hold clues to the origin and evolution of
                                                                             bacteria could survive the extremes of space.
                             life on Earth and the distribution of life
                             in the cosmos.

                         The discoveries of extremophiles have broad-
                         ened the thinking about the nature of life and
                         the range of conditions that are necessary
                         for life to exist. This has implications across
                         the curriculum, bridging geology, chemistry,
                         biology, and planetary science—and the cre-
                         ation of the field of astrobiology, the search
                         for life beyond Earth. This also plays into the
                         broader fascination about life out there that
                         also stimulates claims that go beyond what sci-
                         entific evidence has shown.

Exploring Ice            LIFE IN ICY PLACES                                                     LESSON 8 DIRECTORY MAIN MENU

                         Can Living Cells Survive Freezing                  How do bacteria survive in icy places?
                         Conditions?                                        Multicellular organisms, like mammals,
                         Generally, living cells do not survive freezing.   birds, and human beings, cannot endure
                         Most often, the expansion that takes place as      being frozen, because freezing disrupts their
                         water freezes breaks cellular walls irreparably.   cells, as crystals of ice penetrate the delicate
                         Life can live near ice, at surfaces and edges in   cell membranes and cause them to break
                         meltwater, or in pockets of liquid water within    open and leak their contents. So how do
                         solid ice, but usually life processes are slowed   single-celled organisms like bacteria survive
                         or stopped by ice itself.                          in icy places?

                         Nevertheless, some forms of microbial              Some bacteria that derive nourishment
                         organisms adapt to freezing conditions and         from plants actually accelerate the forma-
                         can find a harbor within ice, suspending            tion of frost that breaks down the plants
                         their bioactivity indefinitely, and then when       cells. Bacteria have also been found to live
                         conditions melt the ice, the organism springs      in clouds and to travel long distances in the
                         back into life, even after thousands of years.     dust and droplets that make up the cloud,
                         Scientists in the field of astrobiology investi-    and eventually return the ground as falling
                         gate extremophiles on Earth, anticipating that     rain or snow.
                         conditions for life may be present beyond          In a population of microbes that flourish in
                         Earth in solar systems around other stars.         the icy cold, many bacteria live as a colony.
                                                                            The freezing and leaking of some individual
                                                                            cells release sugars and proteins that protect
                                                                            the other microbes from freezing. While
                                                                            individuals die, the population as a whole,
                                                                            and the species, survives. How microbes
                                                                            remain viable is not fully understood.

                                                                            There is some evidence that particles of
                                                                            soil and sand atop the Antarctic ice may
                                                                            absorb solar radiation just enough to melt
                                                                            down through the ice, creating pockets
                                                                            where water may form, providing a niche
                                                                            for bacteria.

Exploring Ice            LIFE IN ICY PLACES                                                LESSON 8 DIRECTORY MAIN MENU

                         What’s the importance of Lake Vostok            These discoveries point to probable life
                         in Antarctica?                                  within the underground lake and suggest
                         Satellite radar studies have established that   the sort of icy ecosystem that might exist
                         an exceptionally large lake, roughly the size   on Mars. NASA astrobiologists also see an
                         of Lake Ontario, exists under more than 4       analogy between the environment of Lake
                         km (2.4 miles) of ice sheet. Lake Vostok is     Vostok and a possible sea environment
                         the largest of over 70 sub-glacial lakes in     beneath the ice sheet on Jupiter’s Europa.
                         Antarctica. Estimates of the age of Lake
                         Vostok range from hundreds of thousands
                         to millions of years.

                         Within ice that covers a salty, liquid
                         Antarctic lake scientists have found and
                         revived microbes that were at least 2,800
                         years old and possibly as old as 200,000
                         years. Scientists have discovered teeming
                         microbe colonies that use sunlight filtering
                         through the ice to activate and sustain life
                         when the South Pole tilts toward the sun
                         each year. In fact, the researchers have
                         found surprisingly diverse microorganisms
                         throughout the frozen lake water, supported
                         by the key life-sustaining processes photo-
                         synthesis and atmospheric nitrogen fixation.
                         Previously, most investigators thought little
                         or no biological activity could occur within
                         the ice itself.

Exploring Ice            LIFE IN ICY PLACES                                  LESSON 8 DIRECTORY MAIN MENU

                         ACT OUT THE SCIENCE
                         Whole Group Mime Activity: Movement
                         Integration Mediating Experience
                         This science story plays on the fascinating
                         microbial strategy of individual bacteria
                         releasing sugars and proteins that protect
                         the colony population and leads to species
                         survival. In a sense our own multicellular
                         existence depends on a process of cellular
                         renewal at the boundary of our being. Our
                         outermost layer of skin, hair, nails, are pro-
                         tein structures of cells that shed, individually
                         no longer alive. Our being is a mix of the active
                         living cells and this protective outer coat.


Exploring Ice            LIFE IN ICY PLACES                                                                LESSON 8 DIRECTORY MAIN MENU

                          A Psychrophilic Journey: The science story of psychrophilic (cold-loving) bacteria

                            Narrative                              Movement                             Concept
                            There was once a pair of               Invite all students to participate   Microbes, germs, microorgan-
                            mighty microbes so tiny, you           with partners.                       isms—small microscopic
                            could only see them if you                                                  one-celled forms of life.
                            were looking through a micro-          Get everyone moving together,
                            scope. These microbes were             showing gestures of being cold,      Bacterium, singular;
                            ice-loving germs, each one a           but enjoying it.                     bacteria, plural.
                            psychrophilic bacterium. Well,
                            to be generally specific, these         Have fun with the word               Psychrophilic, meaning
                            bacterium twins have hundreds          psychrophilic, which means           cold-loving, referring to
                            of ice-loving cousins with             cold-loving.                         species that actively thrive
                            names like:                                                                 sub-freezing temperatures of
                            Pseudomonas (soo-dó-mo-nas),           Have fun with these genus            ~ 0º to –10º C and survive by
                            Halomonas (hal-ló-mo-nas),             names, more as sounds and            becoming dormant encased as
                            Hyphomonas (hy-fó-mo-nas),             rhythms as students wiggle           spores in temperatures way
                            Sphingomonas (sfin-gó-mo-nas),          around like bacteria.                below freezing.
                            Psychrobacter (sy-kro-bác-ter),
                            Arthrobacter (ar-thro-bác-ter),
                            Planococcus (plan-o-cók-us),
                            and Halobacillus (hal-o-ba-cíl-lus).

                            One cold, shivery day, these           Have partners mime being             Some species of bacteria
                            two little psychrophilic bacteria      on a leaf of grass, show             are capable of manipulating
                            were feeling hungry on a dewy          being hungry.                        near-freezing dew to freeze
                            leaf of grass. The grass was                                                into frost.
                            very tough to munch on. The            Move arms to transform the
                            bacteria didn’t have big teeth         wateriness of the dew toward         The frost breaks down the leaf
                            like a cow or a sheep or a goat        the iciness of frost.                cells, making it accessible as to
                            or a horse. But they were very                                              the bacteria to obtain nutrients.
                            clever. Conditions were just
                            right so they could chemically
                            coax the dew to freeze into
             PRINT          frost, and the ice crystals
                            crunched the outer leaf cells
                            just enough for the cold-loving
                            bacterium twins to have a feast.       Munch on the leaf.

                            Then they split into several           Partners join up to become a         Generally, the rapid reproduc-
                            more, now there were three             foursome. (Alternatively, tell       tion of bacteria.
                            and four!                              the whole story with tow students
                                                                   up to this point and then add
                                                                   other students.)

                            All of a sudden, a big storm           Wild stormy motions, that            Scientists have discovered
                            came in, with wind and snow,           result in floating cloud motions.     that bacteria not only travel
                            and the four bacteria friends                                               in the clouds, but can also live
                            were swept into the sky along                                               and reproduce during their
                            with dust and debris, up, up, up                                            journeys in the clouds.
                            into the clouds. (continued)

Exploring Ice            LIFE IN ICY PLACES                                                        LESSON 8 DIRECTORY MAIN MENU

                           Narrative                          Movement                          Concept
                           They happened to find a cave
                           in a particle of silicate dust,
                           where they huddled up for the
                           long wild ride.

                           Since they loved the cold, they    Allow students to invent ways     Generally, many species of
                           were having a wonderful time.      to exude the formation of a       bacteria are capable of forming
                           The bacteria had time to each      relatively rigid outer coat.      spore cases around themselves
                           slow themselves down and                                             as environmental conditions
                           form an outer coat, a spore                                          become critical.
                           case, to survive the bitterly
                           cold journey.

                           They traveled for hundreds         Let students “float” about         Bacteria can become the
                           and thousands of miles until       and then become the center        nucleating particles for snow
                           they ended up over Antarctica.     of a snowflake that drifts to      formation in the clouds.
                           As the cloud got colder a          the surface.
                           snowflake began to form
                           around the speck of dust
                           and the bacteria spores.

                           Along with millions and billions   Let students drift slow-          A quick version of what
                           of other snowflakes, they           motion, to become seated          really takes many seasons
                           drifted down, down, down,          on the floor.                      of snow to accumulate and
                           onto to the top of a beautifully                                     form layers of ice.
                           cold glacier in the middle of an
                           Antarctic storm. They were
                           buried under mounds of snow
                           and merged into firn.

                           Then one summery day, when         Let students use their hands      The sunlight strikes the polar
                           the sun shined for months, not     to show the sunlight, the sand,   region indirectly, just enough
                           exactly warmly, but just enough    the warming of the particle       to warm some particles on the
                           to warm a speck of sandy soil      and the melting of the particle   surface to burrow down 7–8
             PRINT         that had blown onto the glacier.   down into the ice.                meters into the ice.
                           The speck melted down into
                           the ice, right next to the speck
                           where the bacteria friends
                           were hiding and waiting just
                           for such a moment to spring
                           back to psychrophilic life.        Let the student stand slowly.

                           Oh, they loved the cold and        Let the whole group work          In cold environments,
                           feasted on the nutrients           collaboratively together.         colonies have greater
                           brought down by the speck,                                           potential for survival.
                           and they split and split some
                           more, until they formed a
                           whole colony of bacteria,
                           thousands of bacteria all
                           helping each other.

Exploring Ice            LIFE IN ICY PLACES                                                              LESSON 8 DIRECTORY MAIN MENU

                           Narrative                             Movement                           Concept
                           Then a marvelous moment               Let students create movements      Deep in glacial ice, trickles
                           occurred a bacterium found            like a water slide.                sometimes form at the bound-
                           a skinny brook of meltwater                                              aries of ice grains.
                           gliding between the ice grains.
                           All the bacteria leaped in and
                           like a watery slide, they slid
                           this way and that way, deeper
                           and deeper into the ice.

                           But then it got really cold. Oh,      Let the outer group of students    While this is still not fully
                           they loved the cold all right,        create a protective coat, while    understood, the outer bacteria
                           but if it got really, really cold,    the inner group huddles.           sacrifice themselves, allowing
                           they huddled together. They all                                          their constituent materials to
                           began to transform themselves                                            affect the surrounding ice, in
                           to spores. The outer group,                                              effect protecting the whole
                           pressured by the grains of ice,                                          colony, giving the inner group
                           released proteins and sugars to                                          the time to repair damage and
                           protect the whole colony—and                                             to reproduce.
                           they stayed like this for hundreds,
                           even thousands of years.

                           Then one day a band of psy-           Let students transform             Scientists discovered the
                           chrophilic astrobiologists drilled    themselves from being              phenomenon of ice-loving or
                           down into the ice and in bring-       bacteria to being the team         psychrophilic bacteria in the
                           ing up the ice-core, they also        of astrobiologists making this     ice-cores in both the Arctic
                           brought up our colony of bac-         discovery, and completing          and the Antarctic. Life is
                           teria. They flew the ice-core          the psychrophilic journey.         everywhere it can be.
                           back to the astrobiology lab,
                           and to their surprise, the scien-
                           tists found that not just one,
                           but that over a hundred cold-
                           loving species of bacteria had
                           found a way to thrive and sur-
                           vive in the extremely icy place,
                           deep in the glacier above the
             PRINT         frozen lakes of Antarctica!

                           So that’s the science story
                           as far as we know of the ice-
                           loving bacteria, the ice-loving
                           astrobiologists and their most
                           psychrophilic journey!

                         Small Group Mime Activity: Movement                        a psychrophilic journey, the story of how
                         Integration Mediating Experience                           cold-loving bacteria thrive and survive in
                         Invite students to form small groups (about                freezing cold places. Encourage students
                         three to five students), create their own                   to act out a sequence that results in under-
                         imaginative mime and narrated story about                  standing about the nature of life in icy places.

Exploring Ice            LIFE IN ICY PLACES                                                      LESSON 8 DIRECTORY MAIN MENU

                         The activity enables students to collect          s   Water.
                         evidence about the observable effects             s   Gallery of images and videos of astrobiol-
                         of freezing on microbial forms of life.               ogists at work in the field.
                         For All Lessons, to Record Reflections,            s   Gallery of images of microbial life and
                         Observations, Calculations, etc.                      effects of microbial activity.
                         s Science Notebooks: writing and
                                                                           s   Gallery of images of extreme environments.
                           drawing utensils.
                                                                           s   Resources about extremophiles,
                         For food freezing exploration                         biomarkers, biosignatures.
                         s A collection of different foods that spoil
                                                                           s   Access to contact with a microbiologist
                           rapidly, such as:
                                                                               or astrobiologists.
                             – Fruit, such as oranges, grapes,
                               strawberries.                               Access to contact with a microbiologist
                             – Vegetables, such as spinach, tomatoes.      or astrobiologists is available through the
                                                                           NASA Astrobiology Institute:
                         s   Access to refrigerator and freezer.
                         s   Thermometers (to measure temperature.         s   Building Bridges with Astrobiology
                             in room, in refrigerator, and in freezer).        Researchers: http: //
                         s   Sterile Petri dishes, or similar containers
                             & resealable plastic bag.                     s   Ask an Astrobiologist:
                                                                               http: //
                         s   Sterile Petri dishes containing nutrient

                         s   Organic materials (bits of food).

Exploring Ice            LIFE IN ICY PLACES                                                   LESSON 8 DIRECTORY MAIN MENU

                         Through discussion, guide students to          PRE K – 2
                         express ideas about life and the conditions    s   Invite students to share their own experi-
                         needed for life to exist, probing especially       ences of finding living things in unusual
                         to draw out their understandings resulting         places. For example: Roly-polys under
                         from their personal experience. Show               a rock? Spiders in a shed?
                         images and videos of astrobiologists at work   s   Guide discussion toward inquiry about
                         in the field, connected to their discoveries        the notion of extreme conditions.
                         about life in extreme conditions, especially
                                                                        s   List the conditions that students say
                         icy conditions.
                                                                            are extreme.

                                                                        s   Build from the student generated list to
                                                                            guide discussion of the range of extreme
                                                                            environments scientists are exploring.

                                                                        s   Ask students to consider how life copes
                                                                            with those conditions.

                                                                        s   Invite students to draw a picture of life
                                                                            in an extreme environment.

                                                                        s   Invite students to consider the range of
                                                                            conditions for life to exist.

                                                                        s   Guide discussion by asking students to share
                                                                            their own ideas about and experiences of
             PRINT                                                          life in unusual and extreme conditions.

                                                                        s   Use these experiences to move toward a
                                                                            discussion of a working definition of
                                                                            extreme and extremophiles in this situation.

                                                                        s   Invite students to draw, write, and share
                                                                            their own experiences of finding living
                                                                            things in unusual places.

Exploring Ice            LIFE IN ICY PLACES                                                    LESSON 8 DIRECTORY MAIN MENU

                         MAIN ACTIVITY
                         This activity introduces the notion that          Diagnose
                         ice preserves evidence of life and can            Listen to student ideas about life. What are
                         harbor some forms of life that suspend            the conditions needed for life to exist? What
                         and then revive their bioactivity.                kind of evidence do we need to establish the
                                                                           presence of life? How does extreme cold
                         PREPARATION                                       affect biological processes? Listen also to
                         Select a familiar group of samples of food        students’ understandings about microbial life,
                         that usually tend to spoil rapidly.               germs, their benefits and threat to human life.

                         s Fruit, such as oranges, grapes, strawberries.   Design
                         s Vegetables, such as spinach, tomatoes.
                                                                           Encourage students to work as collaborative
                         Collect enough Petri dishes to enable each        teams to pose questions and then to design
                         student to have a participatory role (individ-    their ice and life experiment. Help them
                         ually or in context of small groups).             arrange an interview of a working scientist,
                                                                           in person, over the phone, or via email.
                         Set up astrobiology exploratory zones, which
                         display images of extreme environments            Discuss
                         and the diversity of extremophile species,        Discuss the implications of the experiment
                         especially magnified images of bacteria.           with respect to life in extreme environments
                         Explain how to handle samples and Petri           on Earth and in the Solar System. After
                         dishes carefully.                                 speaking directly with a scientist, ideas for
                                                                           further exploration are likely to arise.
                         TEACHING TIPS
                         Explore                                           This activity applies collaborative research
                         Encourage students to probe why we
                                                                           techniques, how to work together to gather
                         refrigerate and freeze food. Engage               information, design an experiment, and
                         student’s experiences of spoiled food, sour       pose questions to a scientist, skills that can
                         milk, and consequences of not recognizing         be applied in other investigations as well.
                         spoilage. Encourage students to consider
                         their own experience of cold weather and
                         how to enjoy the cold.

Exploring Ice            LIFE IN ICY PLACES                                                   LESSON 8 DIRECTORY MAIN MENU

                         WARM-UP AND PRE-ASSESSMENT                       Evoke comments regarding the reaction
                         Present a sample of something tasty and          to the different samples, using guiding
                         delightful that has been frozen.                 questions such as:

                            Likely reaction: Yum, but we have to          s   What distinguishes each of the
                            wait until it thaws out.                          three samples?

                         Present a sample of something tasty and          s   What caused the changes to the food
                         delightful that has been refrigerated.               that spoiled?

                            Likely reaction: Yum, we could eat this       s   Why do we refrigerate and freeze food?
                            right now.                                    s   Why do you think that we keep food in
                         Present a sample of something that once              the refrigerator or the freezer?
                         was tasty and delightful, but is now spoiled.    s   What do you think happens to food that
                            Likely reaction: Yuck, this looks awful!          is left out too long?

                         Follow up with a guided discussion, punctu-      s   What actually happens when food spoils?
                         ated by showing related slides or by referring       What causes food to spoil?
                         to astrobiology zones. Keep track of and         Guide the discussion toward the under-
                         record student ideas.                            standing that microscopic forms of life are
                                                                          responsible for the decomposition that they
                                                                          observe. Use the discussion to probe how
                                                                          familiar students are with an understanding
                                                                          of “germs.” Introduce and use the term
                                                                          microbe to refer to the whole class of
                                                                          microscopic life forms: bacteria, viruses,
                                                                          fungi, and protozoa.

Exploring Ice            LIFE IN ICY PLACES                                                    LESSON 8 DIRECTORY MAIN MENU

                         PROCEDURES                                        Place one sample in a location at room
                         PART 1.                                           temperature, one in the refrigerator, and
                         Ice & Life Experimental Activity                  one in the freezer.

                                                                           Optional: for handling ease, place each dish
                         Spoil the food and Spare the child
                                                                           inside a resealable plastic bag, to avoid the
                         The purpose of this activity is to give
                                                                           likelihood of the cover coming off as students
                         students a taste of astrobiology fieldwork,
                                                                           handle Petri dishes for observation.
                         comparing microbial activity in three tem-
                         perature conditions: room temperature,            Examine each dish daily over the period
                         refrigerated, and frozen.                         of several days, or before and after the
                                                                           weekend. Record observations. (Bacteria
                         Teacher-prepared control dishes (optional):
                                                                           need about four hours to adapt to a new
                         for young children in the classroom, working
                                                                           environment before they begin rapid
                         with nutrient agar is sometimes complicated.
                                                                           growth. Evidence of spoilage may happen
                         Nevertheless, if possible, it would be good to
                                                                           in several hours.)
                         have two kinds control dishes:
                                                                           s   What differences do your observe?
                         1. Sterile Petri dishes with nutrient agar
                            NOT EXPOSED to the air; (should                s   How do you explain your observations?
                            remain clear of microbial growth).             As a follow-up, leave the previously frozen
                         2. Sterile Petri dishes with nutrient agar        sample out at room temperature for several
                            EXPOSED to the air; (should show               days. Ask questions such as:
                            evidence of microbial growth, bacteria,        s   What happens?
                            molds, fungi).
                                                                           s   Does spoilage occur? If it does, how do
                         For each small group, or for each                     you explain it?
                         exploratory zone:                                 s   How do you explain your observations?
                         Prepare several initially sterile Petri dishes,
                         each with a bit of water and a bit of fresh
                         organic material (for example, a piece of
                         lettuce, spinach, grapes, a piece of banana,
                         or other bit of food, something that usually
                         spoils rapidly), expose to air, and then cover.

Exploring Ice            LIFE IN ICY PLACES                                                     LESSON 8 DIRECTORY MAIN MENU

                         What can we conclude about the effect of freezing on bioactivity?
                         Astrobiology Note: Astrobiologists freeze microbial cultures for long-term storage of
                         specimens. Freezing slows bioactivity down, but with thawing, the microbes activate
                         again. Frozen specimens in the field can reactivate, too!

                         Observations and measurements connected to ice and life experiment:

                            Observations                                      Measurements
                             a. Sample at room temperature shows             • Daily observations: draw,
                                evidence of decomposition                      describe, photograph

                             b. Sample in refrigerator shows little          • Daily observations: draw,
                                evidence of decomposition                      describe, photograph

                             c. Sample in freezer shows virtually            • Daily observations: draw,
                                no decomposition                               describe, photograph

                             d. Follow-up: after previously frozen sample    • Daily observations: draw,
                                is left at room temperature, does evidence     describe, photograph
                                of decomposition appear? What does
                                this mean?

                         PART 2.
                                                                              Contact a NASA or local university expert
                         Exploratory Zones: Life in Icy Places                in the field (microbiologist, astrobiologist) to
                         Assemble a collection of resources in viewing
                                                                              create access for students in a collaborative
                         zones around the room: pictures, microscopes         science learning relationship.
                         and slides, videos, articles that show places
                                                                              Encourage students to prepare a focused
                         where life can exist (sea ice, Antarctic rock
                                                                              interview, based on specific questions, if they
                         outcroppings, deep ocean heat vents, clouds),
                                                                              were able to communicate directly with an
                         and recent findings regarding extremophiles
                                                                              astrobiologist or microbiologist working in
                         in icy environments on Earth.
                                                                              the field.
                         Invite students to work in small groups to view
                         the collection of materials and to generate
                         questions to pursue in greater detail.

Exploring Ice            LIFE IN ICY PLACES                                                       LESSON 8 DIRECTORY MAIN MENU

                         What have scientists discovered about ice and life?

                         Research studies connected to ice and life:

                            Discoveries                                     Evidence

                           a. Ice can form around bacteria in               • Cloud chamber experiments
                              the atmosphere                                • Samples from low-lying clouds

                           b. Microbes can survive in very cold climates    • Frozen lake & glacial ice cores
                                                                            • Sea Ice, Lake Ice
                                                                            • Ancient ice, once melted, yields culture
                                                                              of microbial life

                           c. Ice can have occlusions of water where life   • Channels around glacial ice grains
                              can exist                                     • Ice can act to insulate water


Exploring Ice            LIFE IN ICY PLACES                                                     LESSON 8 DIRECTORY MAIN MENU

                         DISCUSSION AND REFLECTION                        Bacterial explanation for Europa’s
                         Does microbial life exist on other               rosy glow
                         planetary bodies in the Solar System?            The red tinge of Europa, one of Jupiter’s
                         With new discoveries about life in               moons, could be caused by frozen bits of
                         extreme conditions on Earth, astrobiolo-         bacteria. Their presence would also help
                         gists are increasingly open to the possibility   explain Europa’s mysterious infrared signal.
                         of microbial life in other places in the Solar   New Scientist, 10:34 11 December 01
                         System. For example, here are the lead
                         headlines and first paragraphs from two
                         articles in the New Scientist, a British
                         science magazine:                                Lead a discussion among students about
                                                                          the possibilities of life in other places in
                         Acidic clouds of Venus could harbour life
                                                                          the Solar System. Guide the students to
                         The acidic clouds of Venus could in fact
                                                                          discern the difference between astrobiol-
                         be hiding life. Unlikely as it sounds, the
                                                                          ogy, which is scientific inquiry about life
                         presence of microbes could neatly explain
                                                                          in the universe, and pseudoscience, that
                         several mysterious observations of the
                                                                          projects images of UFOs, aliens, and
                         planet’s atmosphere.
                                                                          extraterrestrial beings.
                         New Scientist, 10:15 26 September 02

                         http: //


Exploring Ice            LIFE IN ICY PLACES                                                  LESSON 8 DIRECTORY MAIN MENU

                         CURRICULUM CONNECTIONS                        Bacteria also play a role in our well being.
                         With the emphasis on microbial life,          Bacteria within our digestive system help
                         this lesson connects to social studies and    in the process of breaking down nutrients
                         health studies. Infectious diseases caused    for our bodies. Managing bacteria for
                         by microbes such as bacteria and viruses      beneficial effects, such as using oil-eating
                         have had major impacts on the lives of        bacteria to clean-up oil spills, has become
                         people around the world. The pasteuriza-      possible as we grow in our understanding
                         tion of milk, for example, protects against   of microbial life.
                         the passing of bacterial diseases in milk     This lesson also connects to literature.
                         products. Understanding the role of hygiene   Lead a discussion of how science fiction
                         is critical in controlling the presence of    literature, movies, and video games project
                         harmful bacteria and to prevent infection.    imaginative images of life out there. In
                                                                       reality, the life we may first encounter in
                                                                       other places in the Solar System is most
                                                                       likely to be microbial life.


Exploring Ice            LIFE IN ICY PLACES                                                      LESSON 8 DIRECTORY MAIN MENU

                         ASSESSMENT CRITERIA
                         Exemplary                                         Emerging
                         s Students write and illustrate a personal        s Students write and illustrate a description

                           ice and life experience about life in unusual     of conditions where ice preserves and/or
                           places and share it dynamically with both         harbors life and share it with both a small
                           a small group and the whole group.                group and the whole group.

                         s   Students display drawings, constructions,     s   Students pose basic science questions
                             and dynamic kinesthetic models drawn              drawn from their observations and
                             from their science notebooks and web-             research of ice and life.
                             based research.                               s   Students observe examples of life in
                         s   Students identify and extend science              extreme cold.
                             questions drawn from direct observation       s   Student display results using a variety of
                             and extended research about ice and life.         ways to represent examples of ice and life.
                         s   Students explore a rich range of observa-     s   Students ask a rich range of questions
                             tions about ice and life and relate it to         about ice and life.
                             prior shared experiences.
                                                                           s   Students make speculations about possible
                         s   Students ask a rich and extensive range           explanations for ice preserving and/or
                             of questions about ice and life.
                                                                               harboring life.
                         s   Students extend learning by considering       Formative
                             implications of the bioactivity at low        s Students recognize that ice preserves
                             temperatures.                                   life and can harbor life.
                         s   Students relate ideas to whole context        s   Students identify characteristics of life
                             of exploring ice in the Solar System.             in extreme cold conditions.
                                                                           s   Students pose science questions drawn
                                                                               out of the context of researching life in
                                                                               extreme cold.

Exploring Ice            LIFE IN ICY PLACES                                               LESSON 8 DIRECTORY MAIN MENU

                         ast03may_1m.htm                                2004/11/1115_041115_antarctic_lakes.html
                         Article about extremophiles and implications   Article: Does Life Exist in Antarctic Lake
                         for life on Mars                               Buried Under Miles of Ice? John Roach
                                                                        National Geographic News,
                           November 15, 2004
                         Article about extremophiles, Robert Evans,
                         INEEL Research Communications                  usda_course/section0_5_page_2.htm
                         October 1999                                   A very understandable explanation of
                                                                        approaches to store food (irradiation,
                    refrigeration, freezing)
                         Viable extremophiles in ice near Lake Vostok
                                                                        Link to image gallery
                         Bacteria may play a role in the Snow Cycle

                         The Alfred Wegener Institute: Germany’s
                         leading institute for polar research
                         How Sea Ice Can Harbor Life; Ice algae

             PRINT       antarctic_life_021216.html
                         Article about the implications for life
                         on mars Robert Roy Britt
                         16 December 2002


Shared By: