**How, in our modern world, can we find our way, to understand the earth as a gift again?
—Robin Wall Kimmerer, from Braiding Sweetgrass For Young Adults

*
There are no passengers on spaceship Earth.
*We are all crew.
- Marshall McLuhan

***Man’s heart, away from nature, becomes hard; [the Lakota] knew that lack of respect for growing, living things soon led to lack of respect for humans too.
*
-Luther Standing Bear (c.1868-1939)

We live on the Earth. The Earth is ‘our shelter’, our home. We live on mountaintops, in the plains, in the valleys, and on peninsulas and islands. We are able to live on the Earth because of our atmosphere and the topsoil underneath. In fact, the Earth provides us with the atmosphere, the biosphere, the geosphere, and the hydrosphere. Watch Earth Materials and Systems to see what each ecosphere provides and what together they provide for life on Earth. Between these layers, everything we need to live is provided. Almost 8000 miles in diameter, the earth rotates about its axis, which is tilted at 23.5 degrees, and takes approximately 365 days, or one year, to revolve around the sun. The earth receives the sun’s radiation at different angles, and higher and lower levels create the seasons. The planet Earth is a gift. It is our home.

Enjoy this life on Earth. Tread on her gently!

## Activity 1 – Diagram A Section Through The Earth!

Our earth is in a solar system. The diameter of the earth at the equator is 7,926.41 miles (12,756.32 kilometers) or app. 8,000 miles. It turns out that the earth is not a perfect sphere but is actually only 7,901 miles (12,715.43 km) when measured through the poles, making it wider than it is tall, with a slight bulge at the equator. The earth’s shape is known as an ellipsoid or geoid.

First, calculate the difference in the earth’s diameter at the equator and at the poles. Next, calculate how deep you would have to drill to get to the center of the earth. Take a look at Earth’s Mantle which lies between the Earth’s outer crust and the inner core. Draw a section through the layers of the earth and label the different layers. Reading EdGeo’s Earth History will help you understand the 4.6 billion years of Earth’s formation and how scientists and geologists learn about the past. Upload your Earth’s section to the gallery!

## Activity 2 – The Earth is round!

Greek philosophers began to believe that the physical state of the world could be discovered through the study of its natural processes. Early astronomers began making small physical measurements of physical observations of the seasons. It was Eratosthenes of Libya, who came to study at the Lyceum in Athens, surprising measurement of the sun’s cast shadow. Around 240 B.C., Eratosthenes became the chief librarian at the library at Alexandria. In his lifetime he worked in astronomy, mathematics, geography, philosophy, and poetry. One of the foremost scholars of his time, he is celebrated for his simple measurement of the angle of a shadow cast by a stick at noon on the summer solstice in Alexandria. The cast shadow made an angle of about 7.2 degrees or about 1/50 of a complete circle. Once he measured the distance from Syene to Alexandria, he was able to calculate the circumference of the earth!
Copy his equation and draw his diagram measuring the circumference of the earth. Upload it to the gallery!

## Activity 3 – Earth MOVES!

Did you know that the earth that you are standing upon is in constant motion? Not only does the earth as a planet revolve around the sun, its crust is endlessly moving. Under the layers of the earth is intense heat causing the surfaces to pull apart, push together, tumble and split and explode and shoot out lava. The huge plates slowly move together and apart in what is known as plate tectonics. The land on Earth was once one large land mass called Pangaea. Because of continental drift and plate tectonics, we now live on seven continents and travel the five oceans. Discovered when mapping the oceans in the 50’s, the plates move apart along underwater oceanic mountain ridges that erupt with molten rock three times more than volcanoes on land. Check out this Plate Tectonics Pop-Up Book to see how the earth’s surface is constantly in motion or watch this video Plate Tectonics and Large Scale System Interactions and learn about the Tharp-Heezen Map of the ocean floor. Dash the Juan de Fuca Ridge, the Mid-Atlantic Ridge, the Pacific Antarctic Ridge, the East Pacific Ridge, South East Indian Ridge, Southwest Indian Ridge, and Central Indian Ridge. Draw a picture of the earth when the continents were together in a landmass called Pangea and draw the continents as they exist today. Can you see where the continents came from and where they use to fit together?

## Activity 4 – Travel The Continents And Oceans!

Print a map of the earth. Locate the seven continents and the five oceans. Color in the continents making the desert areas yellow, mountain ranges grey and the rest shades of green. Color the oceans and seas blue. Label Africa, Antarctica, Asia, Australia, Europe, North America, and South America. Next label the major oceans and seas.

Travel the World!

## Activity 5 – Earthquakes

Almost every day the surface of the earth moves! Check out this live USGS map of recent earthquakes or Current Earthquakes. Scientists study the wave amplitude, fault size, and amount of slip of EarthQuakes. Using the several Magnitude scales based on an algorithmic amplitude of waves recorded by seismographs, or machines that register in waves the energy expended in the movement of the earth’s crust. More recently the Moment Magnitude Scale and Environmental Seismic Intensity Scale (ESI 2007) are used to measure earthquake intensity. The intensity of earth’s movement is scaled on the effects of the earthquake on the natural environment. These effects are considered to be primary or secondary after earthquakes happen. Primary effects cover immediate surface effects at the seismic source for crustal earthquakes of high magnitude, 5.5-6.0. Secondary effects are due to ground shaking and include landslides, tsunamis, and surface breakage. Watch this video of Natural Hazards to see the cause and effect of activity in the skies and on our earth. Make a map of the largest earthquakes in history or consider modeling an earthquake proof structure!

## Activity 6 – Track An Explorer's Route

In the history of the world, there have been many great explorers who have bravely gone off on journeys to unknown destinations. From the Americas to the South Pole, people have dared to face the challenges of weather and geography to map the ‘corners’ of the earth. For example, watch TEDed’s How Magellen Circumnavigated the World. Pick an explorer from the web and research his or her path and mode of travel. Map the path on a world map, locating key stops, dates, and discoveries.

If you could explore, where would you go?

## Activity 7 – Earth Check Up

&Native people were the first ecologists, as the mythologies, understandings, and technical knowledge were always directly tied to specific ecologies, or specific regions, plants, and animals. The knowledge base itself becomes one of maintaining a thoughtful, proper relationship of those natural forces.
Tewa writer Gregory Cajete, Ph.D., from Native Science: Natural Laws of Interdependence

What is the current health of our planet Earth? If we could take Earth to the doctor, what would the checkup report? When doctors check our health, what vital signs do they check? What if, for starters, we checked Earth’s vital signs? Take a look at the state of our earth. Use the explore links to find out what scientists and researchers are observing. Take a look at the resources of The Habitable Planet. Check earth’s air, water, plant, forest, ocean, and biodiversity quality. Make a chart of what you find. Can you diagnose the health of our Earth? What would you recommend? What does your lifestyle contribute or detract from the planet’s health? Draw the OXFAM Safe and Just Space for Humanity and see what environmental breaches are accelerating climate change. Check suggestions for making changes. Check the advances in making sure all people on Earth have access to clean water, food, shelter, education, work, and opportunity. Post your findings in the gallery.

**Be a caretaker of the health of our Earth!

## Activity 8 – Our Earth is finite

In the 21st century, people are starting to become aware that our earth is finite. It has limits like global temperature keeping the earth and energy climate in balance. Today’s increase in flooding, forest fires, unhealthy air quality, food security, and access to water, has started intense biodiversity loss of the very nonhuman life that people are dependent upon. While more people around the world live a higher quality of life with more comforts, conveniences, and collateral, if everyone in the world lived this way, it would require four earths!! People need to make concentrated changes in what is produced, how it is consumed, and how it can be recycled. It is a charge for education to assist each and every individual in understanding our interdependent relationship with nature and biodiversity and that we must be stewards of nature. The Earth’s health is our health and our health is the Earth’s health. We must each become agents of change to contribute to a more equitable and just world. K12 students make up more than one-quarter of the world’s population. You are our future leaders. What will you do to cooperate, collaborate, and champion change? What will you do to assist the world toward making a more sustainable future?

The Time is now! Earth is calling you!

## Review

• The most necessary ingredient for life on earth is:
• The earth is 5,280 miles in diameter:
• Without this layer, there would be no oxygen or other gases necessary for breathing on earth:
• Earth once contained one large land mass that eventually split into separate pieces:
• Earth belongs to: