# Deep Time and You

Subject:
Math,Science,Social Studies
Lesson Duration:
90 Minutes
Common Core Standards:
6-8.RST.7
State Standards:
NATIONAL/STATE STANDARDS:
NGSS.SEP. 2, NGSS.SEP.8
Thinking Skills:
Remembering: Recalling or recognizing information ideas, and principles. Understanding: Understand the main idea of material heard, viewed, or read. Interpret or summarize the ideas in own words. Applying: Apply an abstract idea in a concrete situation to solve a problem or relate it to a prior experience. Analyzing: Break down a concept or idea into parts and show the relationships among the parts.

### Essential Question

What is a timeline?

### Objective

Students will be able to construct a timeline.
Students will begin to comprehend the magnitude of geologic time.

### Background

The Earth is about 4.5 billion years old, a number too large for people to conceptualize. If we were to shrink the Earth down to the size of a basketball and compress those 4.5 billion years into a few hours we would be able to observe radical changes. Continents would race around the globe, sink beneath the sea, rise up again, smash into other continents, build mountains, and erode back into the sea. Volcanoes would continually erupt and then quickly be weathered away. An astounding array of life would evolve and most of it would pass into extinction seconds later. Asteroids would occasionally slam into Earth. Indeed, the Earth would look like an extraordinarily dynamic little sphere before us.

But from our reference point, change of this magnitude is hard to appreciate. Yet if we begin to grasp the immensity of geologic time, we can begin to recognize the changing nature of Earth.

See "Additional Resources" below for links to introductory materials about the geology of Craters of the Moon.

From the Teacher's Guide to Craters of the Moon.

### Preparation

You will need:

• Adding machine tape (3 or 4 inches wide by about 100 feet)
• Pencils, pens, crayons
• String or yarn
• Use of a large indoor wall while your class is studying about Craters of the Moon

Students will construct timelines using adding machine tape. Completed timelines will be displayed on a wall for reference during the weeks you are studying Craters of the Moon. In subsequent Cultural History and Ecology units, new timelines will be added to the existing ones on the wall. Timelines of different scales will be linked together with string or yarn to show temporal relationships. See Timeline Examples below.

### Procedure

#### Step 1:

Personal Timeline
Have students make a timeline describing events in their own lives:

• Give each student a strip of adding machine tape about two feet long.
• Have them draw a straight line down the length of the tape.
• On the right side have them write "present."
• If the student is 10.5 years old, have them write "11 years ago" at the far left side of the tape.
• Then, let them divide the timeline up into 11 equal increments.
• Finally, have them fill in significant parts of their life with text and pictures. Label it "(Your Name)'s Timeline." See Timeline Examples under "Materials."

#### Step 2:

Age of Earth Timeline
Have the students make a timeline showing the age of the Earth.

• First, discuss the size of a billion. Quiz the students on what they were doing 10, 100, 1000, etc. seconds ago. Let them guess; then tell them how long the time was in minutes, days, or years. They will be astounded at the size of a billion:
 10 seconds ago? 100 seconds ago? (1.3 minutes) 1,000 seconds ago? (16.7 minutes) 1,000,000 seconds ago? (11.5 days) 1,000,000,000 seconds ago? (31.7 years)

• Tell them the Earth is about 4.5 billion years old.
• Cut as long a piece of adding machine tape as your wall will accommodate.
• Have 2-3 students afix the timeline near the bottom of the wall (other time lines will go above it) and mark off 5 equal lengths. Label the marks from left to right "5 billion years ago," "4 billion years ago," and so on. Label it "Earth's Timeline."
• At the 4.5 billion year old mark, write "the Earth is formed." Divide the most recent billion year division into 10 equal, 100,000,000 year increments.

#### Step 3:

Craters of the Moon Timeline

Have students make a timeline showing events at Craters of the Moon.

• Assign several students to cut a timeline about 15 feet long and divide it into 15 equal parts. It should be marked 15,000 years ago, 14,000 years ago, etc. all the way to the present. Label it "Craters of the Moon Timeline." Place it two or three feet over the Earth's Timeline with right sides aligned. Allow enough room in between the strips for a "Life Timeline" you'll do later.

• Other students should make the following labels on separate small pieces of paper (illustrated if they wish) and when completed they should tape them at the appropriate place to the Craters of the Moon Timeline.
 2,000 years ago Broken Top 2,100 years ago Blue Dragon Flow/Indian Tunnel 2,200 years ago Trench Mortar Flat 6,000 years ago Big Cinder 7,400 years ago Grassy Cone 12,000 years ago Sunset Cone 2,500 years ago North Crater 6,000 years ago Big Cinder Butte 6,600 years ago Silent Cone 2,100 years ago Big Craters 1,500 years ago Triple Twist tree on North Crater flow started growing

### Vocabulary

Timeline: A visual representation of the passage of time as a line.
Geologic time: The long period of time occupied by the earth's geologic history.

### Enrichment Activities

The relevance of the dates and places will grow as they build upon the time line in future weeks. Doing this exercise now will help to familiarize students with names of features they will see on their field trip.