Earth is a Habitable Planet

Initial Publication Date: August 4, 2015

Time required to complete this unit:

This page is under development and may be edited at any time. Some resources have not been cataloged, pending project approval.
3 weeks, or 12.5 hours, or 750 minutes (estimated)

Earth Science Content:

Key Terms: habitability, mass extinction, evolution, impact crater, ice age, banded iron formation, hydrothermal vent, methane hydrate, chemosynthesis

Unit Storyline

Earth at the dawn of its existence was an unwelcoming furnace of volcanic activity and noxious gases, hardly the verdant home to countless species that we know today. This transformation required time on a grand scale, on the order of 4.6 billion years, and could not have occurred without a perfect conflux of relative placement - the fabled 'Goldilocks Zone' - and precise universal ingredients.

Built on a core of molten iron and orbiting our sun in the narrowest of life-sustaining bands, the swirling primordial Earth was enmeshed in a raw magnetism that shielded its oceans and early atmosphere from the ionized solar winds. At the same time, the push from our sun was just enough to allow the creation of a life-sustaining climate. The chemosynthetic organisms of old were eclipsed by new lifeforms and a shift to photosynthesis as the primary mechanism of forming organic compounds. Oxygen concentration increased in the atmosphere, diversifying biological communities and as well, the size of organisms. The fossil record of the Cambrian explosion 542 million years ago captures this transformation. Since that time, life has emerged in myriad forms, surviving even the mass extinction events that have threatened to return this third rock back to its inhospitable past. Today, life on Earth occupies a wide range of environments, demonstrating resiliency even in scorching deserts on land and the seemingly uninhabitable depths of the oceanic abyss. The activities in this unit chronicle Earth's evolution from an inhospitable to a habitable planet by examining key events in Earth's history and processes that facilitated this transformation.

Developed by the DIG Texas Blueprints Education Interns Team

Students will be able to (do)

  • Compare and contrast the atmospheres of Earth's "sister" planets to explore the greenhouse effect and its role in Earth's habitability.
  • Develop a model to explain the significance of banded iron deposits in the role of the formation of Earth's atmospheric oxygen.
  • Analyze the evidence for mass extinction both on land and in the ocean.
  • Investigate the contributions of methane hydrates to the Cambrian Explosion.
  • Construct a model of an organism adapted for an extreme environment.

Students will know

  • About conditions required to support life on a planet.
  • Key factors that influence the habitability of life on Earth
  • About the source of Earth's magnetic and why it is important for life on Earth.
  • How volcanic activity contributed to the formation of the solid Earth, its oceans and atmosphere.
  • How interactions between the geosphere, hydrosphere, and atmosphere combine to support the biosphere.
  • Significance of mass extinction events, including how fossils found on land and in the seafloor sediments provide evidence in support of an asteroid impact as the cause of the mass extinction at the end of the Cretaceous period.
  • About life at hydrothermal vents in the deep ocean and chemosynthesis.

Activities

The activities we have selected are congruent with the Next Generation Science Standards (NGSS), and are arranged to build upon one another. Therefore, to follow the storyline we recommend that teachers complete the activities in the order provided. To open an activity in a new tab or window, right click the activity link and select the preferred option.

Conditions That Support Life

View Activity
http://learn.genetics.utah.edu/content/astrobiology/conditions/

In this visualization and interactive from the University of Utah's Genetic Science Learning Center, learners explore the conditions required for life to exist on a planet.

Instructional Strategies: Lecture , Modeling

Resource Type: Visualization (static visualization, animation, simulation)

Time Required: 30 minutes

Shields Up!

View Activity
http://svs.gsfc.nasa.gov/vis/a010000/a010900/a010984/

In this narrated animation from NASA's Goddard Space Flight Center, learners explore how Earth's magnetic field deflects harmful electrically charged particles while allowing solar radiation to penetrate the atmosphere to be absorbed by Earth's surface, making life possible.

Instructional Strategies: Lecture

Resource Type: Video

Time Required: 10 minutes

The Goldilocks Principle: A Model of Atmospheric Gases

View Activity
http://www.ucar.edu/learn/1_1_2_1t.htm

In this activity from UCAR, learners model and compare the atmospheric differences between Earth and its sister planets, Venus and Mars, to support their understanding of the importance of the greenhouse effect on Earth.

Instructional Strategies: Inquiry, Modeling

Resource Type: Laboratory investigation, experiment or demonstration

Time Required: 90 minutes

The 25 Biggest Turning Points in Earth's History

View Activity
http://www.bbc.com/earth/bespoke/story/20150123-earths-25-biggest-turning-points/index.html

This collection of mini-articles from the BBC invites learners to explore the 25 biggest milestones in Earth's History.

Instructional Strategies: Reading

Resource Type: Visualization (static visualization, animation, simulation)

Time Required: 20 minutes

The Origins of the Atmosphere

View Activity
http://volcano.oregonstate.edu/origin-atmosphere

This short reading from Oregon State's Volcano World site discusses the model of volcanic outgassing and its relationship to the formation of Earth's early atmosphere.

Instructional Strategies: Reading

Resource Type: Scholarly article

Time Required: 10 minutes

Clues to Oxygen Formation

View Activity
http://www.learner.org/courses/envsci/visual/animation.php?shortname=anm_ironformations

In this narrated animation from the Annenberg Foundation, learners discover how banded iron formations around the world offer important clues to oxygen formation.

Instructional Strategies: Lecture

Resource Type: Video

Time Required: 5 minutes

What do banded iron formation deposits reveal about the evolution of the atmosphere?

View Activity
https://serc.carleton.edu/NAGTWorkshops/earlyearth/questions/bif.html

In this activity from the NAGT-managed "On the Cutting Edge" collection, learners create a concept sketch to demonstrate their understanding of banded iron formations and discover the significance of these deposits in early Earth's history.

Instructional Strategies: Inquiry, Concept mapping

Resource Type: Classroom learning activity

Time Required: 30 minutes

Life Has A History

View Activity
http://www.ucmp.berkeley.edu/education/explorations/tours/intro/index.html

Instructional Strategies: Inquiry

Resource Type: Laboratory investigation, experiment or demonstration

Time Required:

The Methane Circus


View Activity
http://oceanexplorer.noaa.gov/okeanos/edu/lessonplans/media/09methanecircus.pdf

In this activity from NOAA's Okeanos Explorer Education Materials Collection, learners investigate how methane hydrates might have been involved with the Cambrian explosion.

Instructional Strategies: Inquiry

Resource Type: Laboratory investigation, experiment or demonstration

Time Required: 90 minutes

Mass Extinctions

View Activity
http://www.nhm.ac.uk/nature-online/life/dinosaurs-other-extinct-creatures/mass-extinctions/index.html

This web reading from the United Kingdom's Natural History Museum introduces the learner to the big five extinction events that each eliminated over half of all species on the planet, sometimes in less than a million years.

Instructional Strategies: Lecture

Resource Type: Scholarly article

Time Required: 45 minutes

Mass Extinction

View Activity
http://www.pbs.org/wgbh/nova/earth/mass-extinction.html

Neil de Grasse Tyson and a team of scientists explore the Permian mass extinction in this NOVA Science Now video.

Instructional Strategies: Lecture

Resource Type: Video

Time Required: 14 minutes

Weighing the Evidence for Mass Extinction--In the Ocean

View Activity
http://www.hhmi.org/biointeractive/weighing-evidence-mass-extinction-ocean

In this hands-on activity from the Howard Hughes Medical Institute Biointeractive site students examine images of the types and abundance of foraminifera fossils above and below the K/T boundary in ODP Core 1049C. The change in the sizes of fossil foraminifera and the extinction of a number of species in the core provides evidence in support of a mass extinction event at the K-T boundary.

Instructional Strategies: Inquiry

Resource Type: Laboratory investigation, experiment or demonstration

Time Required: 120 minutes

Weighing the Evidence for a Mass Extinction - On Land

View Activity
http://www.hhmi.org/biointeractive/weighing-evidence-mass-extinction-land

In this lesson from the Howard Hughes Medical Institute Biointeractive website students analyze data and graphs, using images of pollen grains and fern spores in order to create an idea of Earth's living landscape before and after the K/T mass Extinction.

Instructional Strategies: Inquiry

Resource Type: Laboratory investigation, experiment or demonstration

Time Required: 50 minutes

The Day the Mesozoic Died

View Activity
http://www.hhmi.org/biointeractive/day-mesozoic-died

This video from the Howard Hughes Medical Institute Biointeractive site chronicles the extraordinary scientific detective work concerning the long-standing mystery of the decline of the dinosaurs at the end of the Cretaceous period.

Instructional Strategies: Lecture

Resource Type: Video

Time Required: 34 minutes

The Rock that Changed the World

View Activity
http://www.esi.utexas.edu/k-12-a-the-community/hot-science-cool-talks/lecture-archives/the-rock-that-changed-the-world

The University of Texas at Austin Environmental Science Institute's Hot Science-Cool Talk lecture by Dr. Sean Gulick discusses the K/T extinction event, explains how the impact theory came about, and chronicles the exploration of the Chicxulub crater. The talk also addresses the geologic processes associated with impact craters and how they shape rocky planets.

Instructional Strategies: Lecture

Resource Type: PPT presentation

Time Required: 50 minutes

How Mighty Jupiter Could Have Changed Earth's Habitability

View Activity
http://www.astrobio.net/news-exclusive/how-mighty-jupiter-could-have-changed-earths-habitability/

This web article from Astrobiology magazine considers whether Jupiter could have had an influence on the habitability of Earth.

Instructional Strategies: Reading

Resource Type: Scholarly article

Time Required: 30 minutes

TED Talk David Gallo: Life in the Deep Oceans

View Activity
https://www.ted.com/talks/david_gallo_on_life_in_the_deep_oceans?language=en

David Gallo, Director of Special Projects at the Woods Hole Oceanographic Institution, explains the resiliency of life in the seemingly uninhabitable recesses of the deep ocean in this TED Talk.

Instructional Strategies: Lecture

Resource Type: Video

Time Required: 14 minutes

Activity 2: How Do You Get Your Energy?

View Activity
http://www.ridge2000.org/SEAS/downloads/curriculum/seas_unit4_activity2.pdf

In this activity from the Student Experiments at Sea (SEAS) program, learners investigate how hydrothermal vent communities get their energy from chemosysthesis.

Instructional Strategies: Inquiry

Resource Type: Laboratory investigation, experiment or demonstration

Time Required: 90 minutes

Aterra Explorer 4: Create an Organism

View Activity
http://learn.genetics.utah.edu/content/astrobiology/teacher

In this activity from the University of Utah's Genetic Science Learning Center, learners identify the conditions that may support life and the conditions that may be challenging to life in the extreme environment of a fictitious planet. Students then design an organism with features (adaptations) that would allow it to live in the conditions described.

Instructional Strategies: Challenge or problem-solving

Resource Type: Classroom learning activity

Time Required: 45 minutes

Field Trips

Studies that examine how geologists think and learn about the Earth point to the value of field experiences in helping students develop practices that constitute geologic reasoning. We encourage teachers to take students into the field as much as possible. The former recognizes the limitations of the K-12 classroom setting. Some places such as the seafloor are not accessible. To this end, we include ideas for virtual and actual field trips, including oceanic research expeditions. Field campaigns and oceanic expeditions provide a chance to encourage the ability to see features that are important to professional practice. Indeed, many geoscientists report that these experiences are key factors influencing their choice of geoscience as a career.

Virtual Field Trips

Expedition 15: Dark Life at Deep-sea Vents

View Activity
http://www.divediscover.whoi.edu/expedition15/index.html

Dive and Discover's Expedition 15 examines life that is found in one of the most inhospitable and extreme environments, the East Pacific Rise. There are links to daily updates of the expedition, interviews with the scientists on board, and various videos and slideshows that could potentially be selected by the teacher.

Instructional Strategies: Reading

Resource Type: Visualization (static visualization, animation, simulation)

Time Required: 100 minutes

Many Planets, One Earth

Students can take a trip through the formation of Earth with this video that identifies the key conditions that make it habitable.

Scaffolding Notes

Teachers must develop their own individual plan for how they will teach the unit. The learning activities and educational resources in this unit are intended to complement other instructional activities led by the teacher. Many of the selected learning experiences provide links to excellent background preparatory materials, additional hands-on resources, teaching tips, and cross-curricular connections.

Teachers will need to create their own multimedia presentations, deliver lectures and assign ancillary work to their students in order to set the stage for effective use of the learning activities contained herein. Therefore, it is imperative to allocate time to review the activities and background material prior to using the learning experiences in this unit and to probe students for their prior knowledge before starting an activity.

In addition, although some activities may incorporate assessments, teachers may need to create their own assessments to ensure that are appropriate for the students they teach.

Asterisks (*) indicate teacher resource and background information recommendations for activity support.

_________________________________________________________

*Before beginning the activities in this unit, have students download and explore the HHMI Earthviewer app.

HHMI's Biointeractive: EarthViewer

View Activity
https://www.hhmi.org/biointeractive/earthviewer-online-and-downloadable-version

The EarthViewer from the Howard Hughes Medical Institute is an interactive tool for learners to explore the science of deep Earth's history. If used on a computer, the EarthViewer can be run directly online or it can be downloaded to the desktop. The site also provides a link for downloading an app for tablet or smartphone.

Instructional Strategies: Modeling

Resource Type: Visualization (static visualization, animation, simulation)

Time Required: 30 minutes

*As a way to become familiar with the evolution of Earth's atmosphere and to help with background information the notes and materials found at Evolution of the Atmosphere: Composition, Structure and Energy are recommended for review by teachers.

The Conditions that Support Life interactive is a narrated visualization/video that the teacher may choose to have students view by themselves, in pairs, or as a whole class, discussing different talking points at some or all of the "pauses." The teacher may decide to develop focus questions to guide their students so as to facilitate discussion. The short readings on the page below the visualization are important for clarification of key concepts and should not be overlooked. The culminating activity in this unit is an activity that refers back to the information given in this visualization.

The Shields Up! video is helpful as a review or introduction to the Earth's magnetic field, and more importantly, how the magnetic field sustains life on this planet. The teacher may decide to assign focus questions for whole class discussion or pair-share activities to ensure learner understanding.

The Goldilocks Principle: A Model of Atmospheric Gases B includes a detailed lesson plan for the teacher to implement. The teacher will need to time to prepare and collect materials prior to implementation in the classroom. The lesson includes suggestions for student assessment and modification strategies for alternative learners. The activity targets students in grades 6 - 9. One expert reviewer suggests the addition of a higher level and quantitative treatment of the greenhouse effect to support more advanced high school level learners.

The 25 Biggest Turning Points in Earth's History gives learners the opportunity to explore the biggest events in Earth's history through mini articles and accompanying videos. The teacher may decide to have students work in pairs and share, assign for homework, or create a questions or a scavenger-hunt type activity to guide students in their exploration of this resource.

The Origins of the Atmosphere reading could be assigned as a homework assignment in order to prepare students for in class discussion or as preparatory material for the subsequent learning activity, Clues to Oxygen Formation. This short video expands upon the role of banded iron formations in the formation of oxygen in Earth's early atmosphere.

*For additional detail regarding the "Great Oxygenation Event", this article from the BBC's Earth Timeline can be used by the teacher and/or the students as background information giving insight into stromatolites and the cyanobacteria that formed them.

The next learning activity, What do Banded Iron Formation Deposits Reveal about the Evolution of the Atmosphere?, comes from SERC's On the Cutting Edge collection, a repository of resources developed for undergraduate Earth science instruction. However, with careful instructor review, we recommend its use in the high school classroom. The link is a page that describes instructions for the teacher to guide learners through discussion of banded iron formations, including using magnets to examine BIF samples. The instructor then guides learners through the development of a concept sketch to assess their understanding of how BIFs give insight into the evolution of Earth's atmosphere. The teacher should complete such a sketch prior to implementing in the classroom, in order to anticipate any difficulties learners may have in developing a concept sketch.

The Life Has a History module is part of the University of California at Berkeley's Explorations Through Time series. During this tour students learn about geologic time, fossils, ancestral relationships, cladograms, variation, natural selection, and extinction. Each module includes pre and post-tests, focus questions, and answer keys.

The Methane Circus is an investigative activity developed by researchers on NOAA's Okeanos Explorer, and the link to the activity gives the teacher access to an extensive learning guide with instructions and handouts to accompany the investigation. Also a part of the CLEAN collection, this link will direct the teacher to extensive reviewer notes, teaching tips, extensions, and correlations to various literacy standards. Though the original source indicates a grade level of 5-6 for this activity, the content is rigorous and appropriate for use in the high school classroom, especially when student-driven, as opposed to teacher-led. Prior review by the teacher is suggested for successful implementation of this activity.

Mass Extinctions introduces general ideas about mass extinction and emphasizes specific extinction events in Earth's history. The activity requires that students have Internet access. More than 99% of all species that have ever lived on Earth are now extinct. The vast majority (over 95%) died out either because they could not successfully compete for food or other resources, or they failed to adapt to changes in their local environment over tens or even hundreds of millions of years. Teachers might decide to assign the reading as an in-class or outside of class activity with learners taking notes in preparation for classroom discussion about the five major extinctions and what factors lead to these mass extinctions.

NOVA Science Now: Mass Extinction engages the learner in the story of the complete reset of life evolution on our planet as it happened at the end of the Permian Period. This video could be used to encourage discussion of the effects that changes on our planet incur on life, and the possible repercussions of modern activities.

Both Weighing the Evidence for a Mass Extinction: In the Ocean and Weighing the Evidence for a Mass Extinction: On Land support HHMI's short film, The Day the Mesozoic Died. While HHMI suggests showing the film before these two activities, we recommend the learners investigate the evidence for mass extinction through these lab activities and then confirm their results through the viewing of the film. This supports the learners' use of scientific inquiry, an important pedagogical model in Earth science. Alternatively, the included PowerPoint lecture, The Rock That Changed the World, could be utilized instead of the film, as it presents an expert's discussion of the Cretaceous-Tertiary mass extinction event.

*Additionally, the following links give teachers access to supporting materials for K/T extinction activities: The Making Mass Extinctions, Blast from the Past is available as a digital image and PDF and is helpful at looking at the "big picture." The following links are to the images and explanations of the K/T cores: New Evidence of Meteorite Impact Found Beneath the Seafloor, K/T Full Core, and K/T Core Replica Notes. An additional useful teacher resource on the major discoveries and contributions from the ODP and the Joides Resolution can be found at ODP's Greatest Hits.

How Mighty Jupiter Could Have Changed Earth's Habitability is a web article that could be assigned as a homework activity to prepare for a classroom discussion regarding influences to Earth's habitability.

The TED Talk David Gallo: Life in the Deep Oceans engages the learner in what resides deep beneath the oceans' surface, the challenges for life, and the types of organisms that survive in the abyss. This prepares the learner for the subsequent learning activity, How do You Get Your Energy?. In this investigative activity, students will be collecting bacteria from two locations in the school environment and comparing their growth to create correlations to the chemosynthesis that occurs at hydrothermal vents. This lab has extensive teacher prep, creating cultures and gathering materials, so it is important that the teacher preview and plan before implementation in the classroom. The resource includes extensive teacher "tips" and preparation notes in addition to suggestions for levels of student participation.

Aterra Explorer 4: Create an Organism is intended to be a culminating activity for learners to use their knowledge of habitability to evaluate the likelihood of life on an unknown planet and in turn, create an organism with the adaptations necessary to survive in this environment. Prior preparation includes duplication of planet cards and handouts. The teacher might have learners work in pairs or groups and then share with the class their organism and its adaptations, either through presentation or "gallery walk" style.

Next Generation Science Standards

We anticipate that students should be able to achieve the NGSS Performance Expectation(s) listed after completing the activities in this unit. However, we have not carried out educational research to verify this.

HS-ESS2-2. Analyze geoscience data to make the claim that one change to Earth's surface can create feedbacks that cause changes to other Earth systems.

HS-ESS2-4. Use a model to describe how variations in the flow of energy into and out of Earth's systems result in changes in climate.

HS-ESS2-7. Construct an argument based on evidence about the simultaneous coevolution of Earth's systems and life on Earth.

These Performance Expectations integrate the Disciplinary Core Ideas, Cross Cutting Concepts and Science and Engineering Practices of the NGSS as shown in the unit table NGSS Congruence: Earth is a Habitable Planet (Acrobat (PDF) 197kB Jul27 15).

Additional Resources

The recommended additional resources may be used to extend or augment the storyline.

Explorations Through Time

This series of interactive modules explore the history of life on Earth, while focusing on the processes of science. Each module contains suggested lesson plans and an extensive teacher's guide.

Extinctions: Cycles of Life and Death Through Time

This website is with the Hooper Virtual Paleontological Museum. This is the table of contents page for the mass and minor extinctions and for causes of extinctions.

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