SWBAT support an argument that differences in the apparent brightness of the sun compared to other stars is due to their relative distances from Earth.

How is the brightness of a star measured? Students sort data to discover patterns between magnitude and distance of various stars from Earth, and use Data Analysis Cards to interpret and communicate their data.

**This is Day Two of a Four Day Lesson. Click here for Day One of Plaid Pete's Star Lab.**

**On Day One of this investigation, students engaged in a guided exploration where they learned about the life cycle of a star. ****On this second day, students will further their understanding of stars by exploring the concepts of magnitude and how it is affected by distance. This will lead students to consolidate what they have learned to make a claim supported by evidence. Finally, students will explore the different patterns of constellations of stars in the night sky created by the rotation of Earth upon its axis.**

*In this investigation, students continue the work that will lead them to explore the Disciplinary Core Idea of Earth's Place in the Universe: The Universe and its Stars - that the sun is a star that appears larger and brighter than other stars because it's closer, and stars range greatly in their distance from Earth. (5-ESS1-1); Earth and the Solar System - that the orbits of Earth around the sun and of the moon around Earth, together with the rotation of Earth about an axis between its North and South poles, cause observable patterns. These include day and night; daily changes in the length and direction of shadows; and different positions of the sun, moon, and stars at different times of the day, month, and year. (5-ESS1-2); Motion and Stability: Forces and Interactions - that the gravitational force of Earth acting on an object near Earth's surface pulls that object towards the planet's center. (5-PS2-1) and the Crosscutting Concept of Patterns - Similarities and differences in patterns can be used to sort, classify, communicate and analyze simple rates of change for natural phenomena. (5-ESS1-1); Scale, Proportion, and Quantity - Natural objects exist from the very small to the immensely large (5-ESS1-1); and Cause and Effect - Cause and effect relationships are routinely identified and used to explain change (5-PS2-1).*

**Please Note: The Lexile Level for Plaid Pete is Finding Earth's Place in the Universe - Lab Scenario Sheet Lesson 8 is 830 (5th Grade Range is 740 - 1010).**

*The Preparation Time for This Investigation is approximately 15 minutes. *

**Materials Needed:**

One copy for each student of Plaid Pete is Finding Earth's Place in the Universe Lab Sheet - Lesson 9

One copy of Plaid Pete is Finding Earth's Place in the Universe Lab Sheet Key - Lesson 9

One copy for for each team of the Plaid Pete is Finding Earth’s Place in the Universe Sort Cards - Lesson 9 (copied on cardstock, laminated, cut out and placed in sandwich bags)

One copy for each team of Plaid Pete's Data Analysis Cards (Copy on cardstock, laminate, cut out, and place in sandwich bags. You will use these again in Lesson 10.)

One small flashlight

One larger flashlight

**Day One**

**Materials Needed:**

One copy for each student of Plaid Pete is Finding Earth's Place in the Universe - Lab Scenario Sheet - Lesson 8

One copy of Plaid Pete is Finding Earth's Place in the Universe Inquiry Charts - Lesson 8 (I copied these in color on 11x17 ledger paper and laminated them)

One set of Plaid Pete is Finding Earth’s Place in the Universe Inquiry Chart Labels - Lesson 8 (I copied these on card stock, cut them out, and laminated them)

One copy of Plaid Pete is Finding Earth’s Place in the Universe Inquiry Chart Key - Lesson 8

One copy of Plaid Pete is Finding Earth's Place in the Universe Word Wall Cards - Lesson 8

One paper copy for each student of Plaid Pete is Finding Earth's Place in the Universe Word Wall Cards - Lesson 8

5 minutes

I take a few minutes at the beginning of this lesson to review some of the "Burning Questions" that were submitted by students yesterday. I tell my students, *"Listen carefully as we work today and perhaps we will be able to answer some of these, and have some new ones to add to our chart as well." *In this Video Clip we review a question and connect it to an earlier discussion (Warning - student recorded video clip, take your dramamine!).

**Learning Objective & Success Criteria**

**Note: Consistent with the Sheltered Instruction Observation Protocol, I am now including a language objective with each lesson. These objectives were derived from the Washington State ELP Standards Frameworks that are correlated with the CCSS and the NGSS.**

I share the learning objective and success criteria and explain that we will be working on this today and tomorrow - so that they should have achieved these objectives by the end of this series of lessons:

**Learning Objective:** * I can support an argument that differences in the apparent brightness of the sun compared to other stars are due to their relative distances from Earth.*

**Language Objective:** *I can analyze and interpret data in order to engage in an argument from evidence. *[ELP.4-5.7]

**Success Criteria:** *I can correctly complete my lab sheet, analyzing the data, and constructing an argument supported by evidence with my team.*

35 minutes

**Introduce the Video**

I tell my students, "Today we are going to be working with several of the vocabulary concepts that were presented yesterday: apparent magnitude, and absolute magnitude. These are measures of the brightness of stars. I have a video that will help to explain this information, so watch carefully.

I play the video Stargazing Basics 2: Understanding Star Magnitude in Astronomy by Eyes on the Sky.

**Introduce the Task**

After the video has completed, I remind my students that the measures for absolute magnitude and apparent magnitude are in reverse order - that means the smaller the number, the brighter the star. My students are not familiar with the concept of negative numbers, so I draw a number line on the whiteboard and explain that the numbers to the left of 0 are called "negative numbers." I also explain the concept of negative numbers decreasing in size as the digits increase.

I tell my students, "You have a task to complete. I hand out a Plaid Pete is Finding Earth's Place in the Universe Lab Sheet - Lesson 9 to each of my students, and a set of Plaid Pete is Finding Earth’s Place in the Universe Sort Cards - Lesson 9 to each team. I explain that the cards show the 10 brightest stars as seen from Earth, including our sun. We discuss each of the 3 sorting tasks. I give specific directions that they are to sort the cards first, then they are to "write the sort" by filling in the column. Once I am sure that my students understand how to proceed, I give them the signal to begin. As they work, I check in with each team, ensuring that they don't get tripped up by the numbers, and providing reteaching and support, as needed. In this Video Clip, I work with this team to clarify the sort. When teams have finished sorting, their lab sheets look like this Example.

When teams have finished their sorts I tell them, *"Now that we have sorted and ordered this data - it's time to make sense out of it - I know just the tool to help us."*

20 minutes

**Analyze the Data**

I hand out a set of Plaid Pete's Data Analysis Cards to each of my teams. I remind them that they used these in our last unit to look at line graphs. I tell them, *"Today, I would like you to analyze the data you have sorted and see what kinds of patterns you can discover." *I direct my students to turn to the second page of their lab sheets and look at the two prompts: the first asks them to compare the table with the stars listed by least to greatest distance from Earth, with the table that asks them to compare the apparent magnitude of the stars (brightest to dimmest). I want them to see that there is close match between distance and apparent magnitude - that the closer the stars are, the brighter they appear.

The second prompt asks them to compare the distance with the absolute magnitude. I want them to see that these two tables do not match. In fact, even though the sun is the closest star, it is the dimmest of all of the stars listed.

I listen in as my teams work through this process. I am pleased with how well these cards are assisting them in looking at patterns and comparing and contrasting data sets. I ask targeted questions as I check in with each team, asking them to provide evidence for their statements, and to use specific Science Vocabulary. I want my students to pay particular attention to the difference between the apparent magnitude and the absolute magnitude of the sun, so the questions I am asking them provide a nudge in that direction. In this Video Clip 1, I am working with a student to assist him in analyzing the relationship between the data sets. When I realize that he is not understanding the relationship, I back up and use questioning strategies to get him to first see what two sets of data are being compared. In this Video Clip 2, I have determined that this team understands what is being compared, but they are having a difficult time wading through all of the data to determine the relationship. I have them try the strategy of reading the data out loud, and then they are able to use the Data Analysis Cards to describe the relationship.

**Class Share Out**

I ask each team to pick out the two most important discoveries that they believe they have made. I ask the team leaders to get a whiteboard and a marker. Then I ask them to use their Data Analysis Cards to construct their statements on the whiteboard to share with the class. I call on my teams to share out, and we begin a lively discussion about what they have discovered.

I want to make sure that my students don't develop misconceptions. I tell them, *"Although the sun has the lowest absolute magnitude of the stars that we looked at, it is certainly not the dimmest star in our galaxy, or in our universe. As you learned in our first lesson in this star lab - there are billions of stars in our universe and they are at various stages in their life cycles. Stars exist from the very dimmest to the very brightest - not all stars have the same magnitude. This is an important understanding that I want you to take away."*

This is an Example of the second page of a student's lab sheet.

**Demonstration**

I want my students to have a real life demonstration with this idea that they have unearthed from the data - that one star only appears brighter because it is closer in proximity to the Earth. I have a small and a large flashlight. I turn off the lights and close the blinds. I ask one student to hold the larger flashlight at the far end of the room. I hold the smaller flashlight at the front of the room. I call up each of my teams, one at a time and demonstrate that the smaller flashlight looks brighter because it is closer. I then ask the student that I have placed in the far corner of the room to slowly walk towards us so they can see the change as the flashlight gets closer.

I tell my students, *"It's time to wrap up our lesson today, because tomorrow we will be learning a bit more about the most important star of all - the Sun."*

5 minutes

**The Most Surprising Thing . . .**

I pass out strips of paper to each of my students. I write the following sentence stem on the whiteboard: The most surprising thing I learned today was _____.

I ask my students to complete the sentence. I collect the strips and am eager to see what they have to say.

Here is a sample: