Welcome to the first full model of the year for MBER's earth science-integrated biology!
Phenomenon
The Earth is a unique planet, even among its neighbors in the inner solar system, having not only a rocky structure but also oceans, an atmosphere and life!
Question
How did earth get all of the unique features that we described in our list? Where did all of these features of earth come from? How did these various spheres (i.e. geosphere, biosphere, hydrosphere, atmosphere) of earth form?
Driving Question for this Unit:
How did the rocky Earth (the geosphere) initially come to be?
Model Ideas
- Earth formed when many small space rocks collided and came together.
- When meteors (space rocks) combine, their masses add together.
- Gravity increases when 1) the mass of an object increases and/or 2) when the distance between two objects decreases.
- More gravitational attraction caused more collisions as proto-Earth gained mass.
- As more and more nearby space rocks collided with the Earth, the number of nearby space rocks decreased.
- Collisions of space rocks with planets and space rocks with space rocks convert kinetic energy into heat. Increases in the mass or velocity of the objects increases the heat generated during impact.
- As proto-Earth was forming, there were so many collisions producing heat that the solid rocks melted into liquid.
- The proto-Earth was a sphere of lava being constantly hit (and heated) by more space rocks.
- As space rocks decreased in number, there were fewer collisions so the cold empty vacuum of space cooled proto-Earth down. The parts of Earth closest to the surface cooled down first, while the deepest center of earth remained molten rock.
Overview
Transition In: Having realized that Earth is a changing system that may be in peril, we turn toward an exploration of what makes the Earth unique and how it got to be that way.
After generating two lists-- one with characteristics Earth shares with other planets and another that it does not-- we wonder how our unique planet came to be. We decide the first step is to explore the formation of the Earth's rocky geosphere since we wonder if the inner, rocky planets may have all formed in a similar manner. A specific common feature among the inner planets--craters--gives us a place to start exploring our model. Through a lab, we recognize that meteor impacts hold the potential to add mass to a planet as well as a significant amount of energy. This leads us to think that Earth may have formed from the accretion of meteors, dust and gas during the formation of the solar system. The result was a massive planet whose formation accelerated due to gravitational capture of more space rocks over time. As space rocks declined in number (as planets accumulated their mass), the number of impacts declined, Earth cooled and formed a rocky crust atop a molten interior.
Transition Out: After developing a model for the formation of the geosphere, we turn our attention to the other aspects of Earth, the ones that make it more pointedly unique--the atmosphere, the oceans, and life. How did these originate?
Advanced Planning
There are a number of labs, simulations and demos in this unit (and one mathematical calculation) that will require preparation. Please see the teacher guides for each activity for details. Additionally, we've provided a supplemental teacher guide devoted to "Building the Model". You should read this guide as part of your preparation for the unit: this is the first model you will build in earnest with your students, yet in this rather large unit, we don't formally generate the model until Learning Segment 08. The guide will help you to track ideas with your students as you work toward that important moment.
Please also see consider the Earth Science Guides referenced in the teacher slides in the PowerPoint. For this unit, there are three that are particularly germane: Meteors (LS 03), Accretion (LS 04), and Gravity (LS 09).
Segment Title
Learning Segment 01: Exploring Earth (80 minutes)
Overview: We first consider what makes the Earth unique. How is it different from other planets? Through a couple of activities, we develop a list of ways in which the Earth is similar to the other planets of the inner solar system and ways in which it is different.
What we figured out... We’ve identified some ways in which the Earth is unique, and some ways in which it resembles neighboring planets. This sets us up to generate questions and to leverage our ideas about commonalities to develop a Driving Question.
Segment Title
Learning Segment 02: Generating Our Driving Question (30-55 minutes)
Overview: We compile the questions we have. Instead of settling immediately on a broad Driving Question about the formation of the Earth, we engage in a short discussion about the commonalities among the inner planets (including Earth). We then decide to begin our exploration of an overall question about the formation of Earth by first focusing on the geosphere. How did Earth’s rocky structure (the “geosphere”) form?
What we figured out...We have both a broad Driving Question that asks how the Earth came to be as it appears to day, and a more immediate Driving Question that will carry us through this unit. How did the rocky Earth (the geosphere) form?
Segment Title
Learning Segment 03: Impact Craters (55-100 minutes)
Overview: We explore one of the features we think Earth shares with other planets by looking more closely at a Barringer Crater in Arizona. In our exploration, we conclude that it, and other craters on Earth, were indeed caused by space rocks.
What we figured out... We’ve explored the crater in Arizona and have developed a pretty solid evidence-based argument for how a meteor impact could explain its origin. But we’re still wondering what really happens during an impact and decide to first consider what happens to the all of the “stuff” (the matter)—the space rock and the ground.
Segment Title
Learning Segment 04: Impact Craters Lab and Conservation of Mass (55 minutes)
Overview: We explore what happens to matter during an impact by engaging in a lab and tracking the mass of the system both before and after a simulated event.
What we figured out...We see that mass is conserved in our lab simulation, but we wonder if this is what really happens in a high speed impact.
Segment Title
Learning Segment o5: Debating What Actually Happens During Impact (20-30 minutes)
Overview: We consider how realistic the lab might have been when compared to what actually happened at Barringer Crater or other impact sites. We engage in a Four Corners activity, debating our ideas about what might actually happen during an impact.
What we figured out...By problematizing the lab, we recognized that we might not yet understand what happens during an impact. We decide we have questions about both matter and energy. What happens with each when a space rock hits the Earth?
Segment Title
Learning Segment 06: Impact Simulator and Patterns (30-55 minutes)
Overview: We use a web-based simulation to consider how factors like velocity, density of the materials, etc. might affect the outcome of an impact. We also notice these parameters affect the energy involved, inspiring us to begin wondering how energy behaves during impacts.
What we figured out...We see that multiple factors change the outcome of impacts, but now we are more focused on wondering what happens with energy when a space rock hits the ground.
Segment Title
Learning Segment 07: The BBs Lab / Energy Transformation into Heat (110 minutes)
Overview: We explore how energy is involved in impacts through a lab and run some calculations that show us how much energy is released as heat.
What we figured out...We now see that beyond the movement of a lot of matter on the ground, the generation and deposition of heat is a huge consequence of impacts.
Segment Title
Learning Segment 08: Rewind the Clock / Building the Model (55 minutes)
Overview: We finally step back to wonder how impact craters might help us understand how the Earth formed through an activity called “Rewind the Clock”.
What we figured out...We’ve pulled together an accretion-based model of Earth’s formation but have begun to wonder about the role of gravity.
Segment Title
Learning Segment 09: The Role of Gravity (30-55 minutes)
Overview: We explore gravity and consider its role in Earth’s formation.
What we figured out...We now have a fairly complete model for molten Earth.
Segment Title
Learning Segment 10: A Cooled Earth (55 minutes)
Overview: We consider the final pieces of the model, and work to understand how Earth must have cooled enough to form an exterior crust.
What we figured out...Now that we’ve considered both the conditions necessary for cooling and the process of planetary cooling, we have a final model for how the Earth (the geosphere) formed.
Download Resources
| Attachment | Size |
|---|---|
| Download All Formation of the Earth (MBER-LE) Resources | 92.82 MB |