How are we connected to the patterns we see in the sky and space?

This unit builds toward the following NGSS Performance Expectations (PEs):

MS-ESS1-1: Develop and use a model of the Earth-Sun-Moon system to describe the cyclic patterns of lunar phases, eclipses of the Sun and Moon, and seasons. 

MS-ESS1-2: Develop and use a model to describe the role of gravity in the motions within galaxies and the solar system.

MS-PS2-4: Construct and present arguments using evidence to support the claim that gravitational interactions are attractive and depend on the masses of interacting objects.

MS-ESS1-3: Analyze and interpret data to determine scale properties of objects in the solar system. 

MS-PS4-2*: Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials. 

*This performance expectation is developed across multiple units. This unit reinforces or works toward these NGSS PEs that students should have previously developed or will develop more fully in future units. In the OpenSciEd Scope and Sequence, PS4-2 is first built in Unit 6.1 Light & Matter.

• ESS1.A: The Universe and Its Stars
  • Patterns of the apparent motion of the Sun, the Moon, and stars in the sky can be observed, described, predicted, and explained with models. (MS-ESS1-1)
  • Earth and its solar system are part of the Milky Way galaxy, which is one of many galaxies in the universe. (MS-ESS1-2)
• ESS1.B: Earth and the Solar System
  • The solar system consists of the Sun and a collection of objects, including planets, their moons, and asteroids that are held in orbit around the Sun by its gravitational pull on them. (MS-ESS1-2),(MS-ESS1-3)
  • This model of the solar system can explain eclipses of the Sun and the Moon. Earth’s spin axis is fixed in direction over the short-term but tilted relative to its orbit around the Sun. The seasons are a result of that tilt and are caused by the differential intensity of sunlight on different areas of Earth across the year. (MS-ESS1-1)
  • The solar system appears to have formed from a disk of dust and gas, drawn together by gravity. (MS-ESS1-2)
• PS2.B: Types of Interactions 
  • Gravitational forces are always attractive. There is a gravitational force between any two masses, but it is very small except when one or both of the objects have large mass—e.g., Earth and the Sun. (MS-PS2-4)
• PS4.B: Electromagnetic Radiation 
  • A wave model of light is useful for explaining brightness, color, and the frequency-dependent bending of light at a surface between media. (MS-PS4-2)
  • However, because light can travel through space, it cannot be a matter wave, like sound or water waves. (MS-PS4-2)

• Developing and Using Models: Students develop, use, and revise models beginning in Lesson 1 and throughout the unit to explain patterns in the sky ranging from why Manhattahenge occurs twice a year in the same spot, why the seasons in Australia are opposite of seasons in the Northern Hemisphere, why the Moon appears redder during a lunar eclipse but does not go completely dark, why planets go around the Sun and moons go around planets, our place in the solar system and galaxy, and more. 
• Analyzing and Interpreting Data: Students use multiple graphical displays (e.g., maps, scatter plots) of large data sets to identify and explain patterns in sky (such as solar elevation, length of day, location and paths of motion for objects in the sky, and the organization of the solar system. 
• Obtaining, Evaluating, and Communicating Information: Throughout the unit students are gathering, reading, synthesizing and information from multiple sources (e.g., text, data, maps, graphs, images). This is an 8th grade unit toward the end of the year, so students have already had much experience in this practice so while students are given several close reading or listening protocols, some of the scaffolding has been removed from previous units so they can execute the practice on their own.

• Patterns: From the start of Lesson 1, students are noticing patterns in the sky and return several times throughout the unit with their community guide to make note of more patterns they and others feel connected to and observe in the sky. This is built out in Lessons 2 and 3 as they begin to notice repeating patterns not just over days but thousands of years, throughout the unit, and that those patterns can be expanded to systems at great scale such as the organization of the solar system and galaxies due to gravitational forces. 
• Scale, Proportion, and Quantity; Students will gradually build out to the vast scale of the universe starting in Lesson 1 by modeling Manhattanhenge, which just involves a two-object system at one scale, to chose another pattern they feel connected to in order to model from different perspectives, and working toward a model with multiple scales between them in Lesson 17, including galaxies, stars, and additional objects/subsystems in the solar system. 
• System and System Models: Integrated in the Lesson 1 initial models to explain a pattern in the sky chosen by each student is students beginning to make sense of the parts and interactions in the system to explain the causality of their model. Models throughout the unit link components about the motion, positions, and appearance of objects within their subsystems and placement within larger systems. By Lesson 17, students can model each individual subsystem zooming in on the parts and interactions from a galactic scale all the way down to a two-object system, such as the Earth-Moon or Earth-Sun systems. 
• The unit also includes opportunities to practice using Cause and Effect, Stability and Change, and Structure and Function.

This unit is the fourth OpenSciEd 8th grade unit and designed to be taught just after Magnets Unit in the OpenSciEd Scope and Sequence. As such, it can leverage ideas about distance forces and field-based thinking, which is especially helpful where in the space above the Earth and Moon and between them gravitational forces would be found, which lays the groundwork for even larger scale system organization and motion due to gravity.

Additionally, another prior unit, OpenSciEd Unit 6.3: Why does a lot of hail, rain, or snow fall at some times and not others? (Storms Unit), can provide science ideas for students as they they investigate the effect of changes in the atmosphere (or even any atmosphere versus no atmosphere) on the apparent color of the Moon during a lunar eclipse or other phenomena in the sky, such as rainbows and sun dogs.

The unit is organized into four lesson sets. Lessons 1–5 focus on developing science ideas about the Earth-Sun system. In Lessons 6–7, students add the Moon into the system and are left wondering why lunar eclipses do not go completely dark. This leads them to investigate more phenomena related to color and light in lessons 8–12, in order to explain the redder color of the Moon during lunar eclipses. In Lesson 13, students note that their questions can no longer be answered just by observations from Earth and their unaided eyes, which motivates them to use tools to see better and farther into space, expanding the scale of their models. This drives them to wonder about why the solar system is organized the way it is and how it got to be that way, which motivates them to investigate how gravitational interactions dictate the organization and motion of objects within each system and how this holds true for multiple scales and subsystems in the final lesson set, Lessons 13–17.

This is the fourth unit in 8th grade in the OpenSciEd Scope and Sequence. Given this placement, several modifications would need to be made if teaching this unit earlier or later in the middle school curriculum. These include the following adjustments:

• If taught before OpenSciEd OpenSciEd Unit 8.1: Why do things sometimes get damaged when they hit each other? (Collisions Unit) or OpenSciEd Unit 8.3: How can a magnet move another object without touching it? (Magnets Unit), supplemental teaching of the definitions of forces would be required to help student model of what causes gravitational forces, why they vary, and why they can produce relatively y and stable orbits in some conditionsThese ideas are leveraged in Lesson 13 and beyond in this unit.

• From OpenSciEd Unit 8.1: Why do things sometimes get damaged when they hit each other? (Collisions Unit) or OpenSciEd Unit 8.3: How can a magnet move another object without touching it? (Magnets Unit): Force pairs are the result of the interaction of two objects or systems. There are no single forces. Each force in a force pair is equal in strength, opposite in direction, and acting on a different part of the system or object in the system.
• From OpenSciEd Unit 8.3: How can a magnet move another object without touching it? (Magnets Unit): Some forces act a distance rather than through contact between matter. Magnetic fields can be used to map and visualize the direction and strength of magnetic forces at various distances from one or more objects in a system. Distance affects the strength of these forces.

• If taught before OpenSciEd Unit 8.1 (or at the start of the school year), supplemental teaching of classroom norms, setting up the Driving Question Board, and asking open-ended and testable questions would need to be added. (These supports are built into 8.1.)

The following are example options to shorten or condense parts of the unit without eliminating important sensemaking for students:

• If your context dictates shorter amounts of time for a unit or you need to break the unit up into smaller parts: Chunk the unit into Lessons 1–5 (Lesson Set 1), 6–7 (Lesson Set 2), 8–12 (Lesson Set 3), and 13–17 (Lesson Set 4). Lesson Sets 1 and 2 should be taught in sequence and before Lesson Set 4, but Lesson Set 3 could be skipped if you do not need to address MS PS4-2, or it could be moved to be taught after Lesson Set 4. If you do the latter, you would need to adapt the navigation into Lesson 8.
• Lesson Set 3 (Lessons 8–12): If students do not have questions about color and light or your state or district does not require that Physical Science Performance Expectations be a part of this unit then you can skip Lesson Set 3 (Lessons 8–12).  
• Lesson 4: If students don’t have as many questions about deep space interactions, you may want to trim some of the lessons from Lesson Set 4 (Lesson 13–17).

To extend or enhance the unit, consider the following:

• Many lessons: Within many lessons are extension readings, videos, simulations, or activities offered as alternates or home learning. If you find that students are highly engaged or looking for a challenge, offer these readings as either in-class or home learning extensions.
• All lessons: Remove scaffolds provided with Science and Engineering Practices as a way to give students more independent work with the elements of these practices.

This unit is not math intensive. Prerequisite math concepts from students’ math classes include the following:

• CCSS.MATH.CONTENT.7.RP.A.1 Compute unit rates associated with ratios of fractions, including ratios of lengths, areas, and other quantities measured in like or different units.
• CCSS.MATH.CONTENT.7.RP.A.1 Compute unit rates associated with ratios of fractions, including ratios of lengths, areas, and other quantities measured in like or different units.

OpenSciEd units are designed to promote equitable access to high-quality science learning experiences for all students. Each unit includes strategies that are integrated throughout the OpenSciEd routines and are intended to increase relevance and provide access to science learning for all students. OpenSciEd units support these equity goals through several specific strategies such as:

1. integrating Universal Design for Learning (UDL) Principles during the unit design process to reduce potential barriers and provide more accessible ways in which students can engage in learning experiences;
2. developing and supporting classroom norms that provide a safe learning culture;
3. supporting classroom discourse to promote students in developing, sharing, and revising their ideas; and
4. specific strategies to supporting emerging multilingual students in science classrooms.

Many of these strategies are discussed in the teacher guides in sidebar callout boxes titled “Attending to Equity” and subheadings such as “Supporting Emerging Multilingual Learners” or “Supporting Universal Design for Learning.” Other callout boxes with strategies are found as “Additional Guidance”, “Alternate Activity,” and “Key Ideas” and various discussion callouts. Finally, each unit includes the development of a Word Wall as part of students’ routines to “earning” or “encountering” scientific language.

For more information about each of these different strategies with example artifacts, please see the OpenSciEd Teacher Handbook.

• Jamie Deutch Noll, Unit Lead, Northwestern University
• Zoë Buck Bracey, Field Test Unit Lead & Advisor, BSCS Science Learning
• Thomas Clayton, Writer, Advisory Team, and Pilot Teacher, Columbia Middle School, Berkeley Heights, NJ
• Molly Ewing, Writer, The Charles A. Dana Center, The University of Texas at Austin
• Gail Housman, Writer & Reviewer, Northwestern University
• Shelley LeDoux, Writer, The Charles A. Dana Center, The University of Texas at Austin
• Chris Newlan, Writer, David Wooster Middle School, Stratford, CT
• Michael Novak, Writer, Reviewer, & Conceptual Design, Northwestern University
• William Reed, Writer, Gwendolyn Brooks College Preparatory Academy, Chicago Public Schools
• Nicole Vick, Writer, BSCS Science Learning
• Rachel Connolly, PhD., Content Advisor/Media Designer, MIT Media Lab
• Sergio Salgado, Podcast development, Furnace FPS
• Katie Van Horne, Assessment Specialist, Concolor Research
• Christina Schwarz, Unit Advisory Chair, Michigan State University
• Christina Murzymski, Project Coordinator, Northwestern University

BSCS Science Learning

• Rosemi Mederos, Copyeditor, Independent Contractor
• Stacey Luce, Copyeditor and Editorial Production Lead
• Renée DeVaul, Project Coordinator and Copyeditor
• Valerie Maltese, Marketing Specialist & Project Coordinator
• Chris Moraine, Multimedia Graphic Designer
• Kate Chambers, Multimedia Graphic Designer

An integral component of OpenSciEd’s development process is external validation of alignment to the Next Generation Science Standards by NextGenScience’s Science Peer Review Panel using the EQuIP Rubric for Science. We are proud that this unit has been identified as a quality example of a science unit. You can find additional information about the EQuIP rubric and the peer review process at the nextgenscience.org website.