Earth Science Enterprise

Night Lights
This investigation for grades 5–8 is reprinted from the NASA-funded 

Mission Geography curriculum. The entire K–12 curriculum can be 

downloaded from http://www.missiongeography.org

Module 2 Educator’s Guide Investigation 1

Where do we choose

to live and why?

Investigation Overview

In this investigation, students use a nighttime image to observe areas of light

across the United States and to identify patterns and spatial distributions of

human settlements. They explain the reasons for these patterns by answering

questions and making inferences about what they observe. Then this knowledge

is applied to identify similar patterns and spatial distributions on an unidentified

region of the world using a color topographic map and nighttime image.

Time required: One or two 45-minute sessions

Materials/Resources 

Briefing and Logs 1, 2, and 2.2 (one copy for each student)

Figure 2: United States at night puzzle (one per student or 

student group) 

Figure 5: United States relief map (one per student or 

student group)

U.S. road/travel map or atlas

World map or globe

Overhead transparency sheet 

Overhead markers (light colors)

Clear cellophane tape

Scissors

Content Preview

The spatial concepts of pattern, dispersion, and density help to analyze geographic distributions. Maps and images of the United States and other areas of

the world provide the information needed to describe and explain the spatial distribution of settlements.

Classroom Procedures

Beginning the Investigation

1. To begin the investigation, have students examine a U.S. road map and discuss

the distribution of the population and human settlement features such as cities,

highways, transportation hubs, and other areas. A classroom atlas can be used,

or U.S. road maps can be purchased at most stores or local travel agencies.

2. Have students identify and list any patterns they see. Some pattern examples

are large concentrations of settlements separated by what appears to be

unoccupied space, lines of settlement near water, and settlements located

with respect to landforms, such as at the foot of mountains. 

Geography Standards

Standard 1: 

The World in Spatial Terms

How to use maps and other geographic

representations, tools, and technologies

to acquire, process, and report information from a spatial perspective

• Use geographic tools and technologies to pose and answer questions

about spatial distributions and patterns on Earth.

Standard 3:

The World in Spatial Terms

How to analyze the spatial organization

of people, places, and environments on

Earth’s surface

• Analyze and explain distributions of

physical and human phenomena

with respect to spatial patterns,

arrangements, and associations.

Geography Skills

Skill Set 4: 

Analyzing Geographic Information

• Interpret information obtained from

maps, aerial photographs, satelliteproduced images, and geographic

information systems.

• Interpret and synthesize information

obtained from a variety of sources—

graphs, charts, tables, diagrams,

texts, photographs, documents, and

interviews.

Skill Set 5: 

Answering Geographic Questions

• Make generalizations and assess

their validity. 

• Develop and present combinations

of geographic information to answer

geographic questions.
Module 2 Educator’s Guide Investigation 1

3. Allow students to discuss the following questions: 

• Why are some areas empty and some areas more

densely populated? (Due to physical features such as

water bodies, mountain ranges, or deserts.) 

• How are these areas connected to each other? (Via

roads, rails, or air transportation.)

• Where do most of the larger cities seem to be located?

(In the eastern part of the country and along coasts.)

Why? (Historical settlement pattern, rainfall, agriculture.)

4. Three important terms associated with spatial distribution

are used in this investigation: pattern, dispersion, and density. Have students define these terms in a class discussion

or by using a dictionary. As an example of spatial distribution, have the students apply the new terms to the classroom setup. For example, what is the pattern of desks and

chairs, and how dispersed or densely arranged are they?

Developing the Investigation

5. The investigation is divided into three sections that build

upon each other. Each section has a series of questions

that students answer. Students answer the questions on

their own, in small groups, or in an educator-guided class

discussion. The answers are based on what students

observe in the images and the maps provided. A U.S. road

map is needed. A shaded relief map of the United States

(Figure 5) will be needed. 

6. Distribute and have students read the Briefing. 

7. Distribute Log 1. It guides students to a basic understanding of spatial concepts associated with human settlement

patterns by using an image of the northeast region of the

United States. The image shows the nighttime lights in this

region. Discuss the information about spatial concepts with

the students to assure their understanding before proceeding with the questions. 

8. Distribute and read copies of the student pages for Log 2

of this investigation. Log 2 builds upon what the students

learned in Log 1. It uses a different image. The students

must first assemble the puzzle made from pieces of an

image of the nighttime lights of the United States and then

answer questions about what they observe in the assembled image. This allows them to develop a better understanding of human settlement patterns. The questions are

divided into three sections. Each level builds to a higher

level of skills. 

9. Have students cut out each segment of the U.S. image

puzzle and assemble them. Ask them to use any patterns

they see in each segment to guide them in the task.

Students should use clear tape to attach the segments.

Once the image is assembled, have students tape a clear

overhead transparency over the image to allow them to use

markers to label and identify the regions discussed in the

questions they are to answer.

10. Instruct students to use their assembled U.S. image to

answer the questions in Log 2.

Concluding the Investigation

11. In concluding the investigation, have students develop new

questions that can be asked about the image. They must

also be prepared to answer their new questions. 

12. Guide students into discussions of possible future settlement patterns and influences of future population growth in

the United States. An example may be that cities and urban

areas continue to spread out using more and more land.

Future settlement patterns may be influenced by road

development, development of automated, computer-controlled autos, high-speed rail travel, and information technology such as computers and other electronic devices

which allow people to work away from a specific factory or

office and thus avoid commuting to work.

Background

Settlement Patterns

Why do you live where you live? Where do people choose to

live? Why do they choose to live there? People have lived on

Earth for thousands of years. Throughout history they have chosen particular settlement locations for many practical reasons.

For just as many reasons they have packed up and moved to

settle in other areas. Sometimes bloody wars have been fought

over the right to settle in a particular region. Also, natural hazards such as floods, earthquakes, and climate changes have

influenced people to change the locations of their settlements.

Cities, highways, roads, agricultural areas, industrial regions,

and transportation hubs around the world are factors that contribute to the formation of human systems. When the United

States was settled, early settlements began in the east and

gradually moved westward. Could this be the reason the eastern United States is more densely populated than the west?

What if the settlements began in the west and moved eastward

instead? How would the United States look today? 
Module 2 Educator’s Guide Investigation 1

NASA has been observing and studying Earth since 1958 with

aircraft, spacecraft, satellites, and humans. These observations

have generated millions of images and tremendous amounts of

data. NASA Earth observations help geographers worldwide to

study and answer many questions about human migration and

settlement patterns. Where will human settlements be 10 years,

20 years, or even 100 years from now? Can humans build settlements on other worlds like Mars or our Moon? Will settlements of other planets become a necessity? 

Nighttime Image

This map is a compilation of satellite images from the National

Oceanic and Atmospheric Administration (NOAA), the National

Geographical Data Center (NGDC), and the Defense

Meteorological Satellite Program (DMSP) that show the continental United States at night. The image of the U.S. nighttime

lights was derived from cloud-free portions of 231 orbits

(October 1994 to March 1995) of DMSP Operational Linescan

System (OLS) data. The majority of the detected features are

lights from cities and towns. The arrangement of lights on this

map is called a spatial distribution. 

Spatial Distribution Concepts

There are three important concepts in locating items in space.

They are pattern, dispersion, and density. Pattern refers to the

arrangement of items within a distribution in terms of density,

clustering, alignment, and orientation. Dispersion refers to

whether items are clustered or spread out. Density means the

number of items within a defined area. Examining the distribution of lights across the United States will help students understand these three concepts. 

Evaluation

Log 1

1. Night

2. Space

3. Population

4. Absence of population

5. No

6. Students should see population clusters, linear

arrangements of population, and even distribution

and spacing between clusters.

Log 2

1. Answers may vary.

2. They are lakes.

3. Gulf of Mexico; offshore platforms

4. Rugged, arid terrain discourages population.

5. Answers will vary.

6. Answers will vary.

7. More people live along the coast.

8. Answers will vary.

9. Answers will vary.

10. Students may see that population densities are

greater in the eastern portion of the United States

than in the western portion.

11. Students may see linear patterns running east-west

and north-south in the west and trending southwest

to northeast in the east following the Appalachians.

Answers will vary.

12. Students may observe that population is least dense

in the drier regions of the United States.

13. Answers will vary, but there is a relationship between

population and elevation and relief.

Resources

NASA Spacelink

http://spacelink.nasa.gov/

NASA Earth Science Enterprise

http://www.earth.nasa.gov/

National Oceanic and Atmospheric Administration (NOAA)

http://www.noaa.gov/

National Geophysical Data Center (NGDC)

http://www.ngdc.noaa.gov/

Defense Meteorological Satellite Program (DMSP)

http://www.ngdc.noaa.gov/dmsp/dmsp.html

U.S. Geological Survey (USGS)

http://www.usgs.gov/

Central Operation of Resources for Educators (CORE) was

established for the national and international distribution of

NASA-produced educational materials in multimedia format.

Educators can obtain a catalogue and an order form via the

CORE Web site at http://core.nasa.gov

Educator Resource Center Network (ERCN) 

To make additional information available to the education community, NASA has created the NASA Educator Resource

Center (ERC) network. Educators may preview, copy, or

receive NASA materials at these sites. Phone calls are welcome if you are unable to visit the ERC that serves your geographic area. A complete list of ERCs is available electronically

via NASA Spacelink at http://spacelink.nasa.gov/ercn
Module 2, Investigation 1: Briefing

Where do we choose to live and why?

Background

Why do you live where you live? Where do people choose to live?

Why do they choose those places? People have lived on Earth for

thousands of years. Throughout history they have chosen particular settlement locations for many practical reasons. For just as

many reasons they have packed up and moved to settle in other

areas. Sometimes bloody wars have been fought over the right to

settle in a particular region. Also, natural hazards such as floods,

earthquakes, and climate changes have caused people’s decisions to change the locations of their settlements. 

Cities, highways, roads, agricultural areas, industrial regions, and

transportation hubs around the world are factors that contribute

to forming human systems. When the United States was settled,

early settlements began in the east and gradually moved westward. Could this be the reason the eastern United States is more

densely populated than the west? How does this historical migration affect current population patterns in the United States? What

if the settlements had grown in the west and moved eastward

instead? How would the United States look today? 

NASA has been observing and studying Earth since 1958.

These observations have been made with aircraft, spacecraft,

satellites, and humans on the ground. These observations have

generated millions of images and tremendous amounts of data.

NASA Earth observations have helped geographers worldwide

study and answer many questions about human migration and

settlement patterns by providing researchers with large-area

views of our planet. Where will human settlements be 10 years,

20 years, or even 100 years from now? Can humans build settlements on other planets like Mars or our Moon? Will settlements of other planets become a necessity? 

In this investigation, we look at one region of Earth using some

unique and interesting perspectives including: images of Earth

taken from space, a relief map, and a road map. Using these

views we identify where human settlements are found and why

these settlement patterns exist.

Objectives

Upon completion of this investigation, you will:

• understand different ways of observing Earth,

• understand ideas of spatial distribution and how these are

used to understand human settlement patterns, and 

• identify human settlements and patterns using maps and

images.

In this investigation, you will learn spatial distribution concepts:

pattern, dispersion, and density. You will accomplish this using

an image of an unidentified location on Earth and answering

questions about what you observe in that image. 

Spatial Concepts

The arrangement of things on Earth’s surface is called spatial

distribution. Observe these six sets of dots. Each square represents an equal area. Each one illustrates an important concept

in the location of items in space. They are pattern, dispersion,

and density. Pattern is the arrangement and design in the distribution. Dispersion relates to whether items are clustered or

spread out. Density refers to the number of items or observations within a defined area.

Pattern

Dispersion

Density
To Observe, Characterize, Predict and 

Respond to Global and Regional Changes

Earth System Science: 

NASA’s Earth Science Enterprise researches the Earth as a group of global

interactive systems. Based on this research informed decisions are made

about environmental trends, protecting our planet, and future quality of life. 

Farmers, geologists, economists, and city planners interpret remote sensing

imagery in order to monitor local and regional changes. Scientists interpret

imagery for broad geographic understanding of global ecosystems, and to

study the relationship between human activities and the impact upon societal, economic, and political issues. 

Information about this composite satellite image:

The city night lights in this picture connect you to people living in an urban

community. Each point of light represents 2,500 people or 427 family units

per km2 ± 5 percent. Light from moving trains, planes, cars, boats, and

water and full moon reflections were removed.

The satellite data used to make this image were collected by the

Westinghouse broad-band visible to near infrared (0.4 to 1.1 microns) optical sensor with a spatial resolution of 2.7 km2

. Between fall 1994 and spring

1995, the sensor collected data during 231 ascending polar orbital paths

using 3,000 km swaths, with a whisk-broom oscillating pendulum motion at

a rate of 101 minutes per orbital period, at an average altitude of 830 km.

The National Ocean and Atmospheric Administration’s National

Geophysical Data Center and the Defense Meteorological Satellite

Program’s Operational Linescan System provided data to NASA

Goddard Space Flight Center and Bowie State University in order to

render this image of global urban lights. Dr. Marc Imhoff is the Principal

Investigator for this project at NASA.

Related References and Resources:

“Remote Sensing Environment” Feb. 1997, Pub. 

Elsevier Science, Inc. NY, NY.

http://www.elsevier.nl/locate/rse

http://www.ngdc.noaa.gov/dmsp/descriptions/doc_ols.html 

http://www.missiongeography.org

http://earth.nasa.gov

http://www.usgs.gov

http://www.cet.edu/essea

http://www.eoscenter.com

http://pumas.jpl.nasa.gov

http://eospso.gsfc.nasa.gov 

http://pumas.jpl.nasa.gov

http://www.globe.gov

http://earthobservatory.nasa.gov/Newsroom/NewImages/

images.php3?img_id=4333

http://esto.nasa.gov

National Aeronautics and

Space Administration

Goddard Space Flight Center

City Night Lights

Earth Science Technology

Explores our Home Planet

Classroom Purpose, Education Level 9–12

Technology is used to access, process, visualize, and communicate data

about Earth Science. Viewing urban lights from the vantage point of satellites enables us to see patterns of urbanization. Urbanization interests the

science community because of the way it influences global climate change,

and economic and biological sustainability.

Objectives: 

1. The student will be able to interpret Earth System Science satellite

imagery and explain the relationship between urban development,

geography, and the global ecosystem.

2. The student will be able to apply knowledge of satellite urban imagery

to additional interdisciplinary learning activities within science, math,

geography, social studies, and technology. 

Materials needed: World Atlas Map

Procedures for Discussing Real-Life Applications:

1. Place students into eight geographical small groups:

a) Africa and Egypt

b) Australia, Fiji, and New Zealand

c) Cambodia, Laos, Malaysia, and Vietnam

d) China, Japan, Korea, and Taiwan

e) Europe, Iceland, and Netherlands

f) India, Middle East, and Tibet

g) Central and South America

h) Kazakhstan, Russia, and Uzbekistan

2. Measure: Direct each group to determine the number of satellite

paths required in compiling the image of their geographic region.

(Formula is width of the geographical area in km, divided by the swath

width of 3,000 km.) 

3. Interpret: Have each small group use the satellite image to locate,

within their region, the major cities, landforms such as water bodies, mountains, and plains, and transportation routes. Use additional maps or an atlas to verify the cities, landforms, and

transportation routes they identified. 

4. Explore: Have student groups use a map or an atlas to identify

vegetation, food crops, grazing areas, and trade routes that may

have contributed to the urbanization in their region. 

5. Earth Science: Explain the processing skills within Earth System

Science of observing, characterizing, understanding, predicting and

responding to changes in the relationship between the ecosystem and

urban development. Q. What would happen if the average regional

temperature increased or decreased by 10°F (5.6°C)? Using logical

progressions, analyze the risks and benefits of human (urban) induced

changes on the environment. Use a sequence of assumptions that

moves your thought process from implementation, to consequences,

to conclusion, and then to predicting future outcomes. 

6. Physical Science: Explain and apply the four key concepts that guide

most scientific investigations: balance of energy, system feedback, life

interactions, and change over time. Encourage each geographic group

to use intuitive problem solving skills, to present a concept map predicting cause and effect, about motion and forces, and interaction of

matter within ecosystems. Q. How is urban development a “force of

change” on the balance of the regional and global ecosystem?

7. Life Science: Explain the interdependence of organisms within living

systems. Living things need water for survival. Q. What would happen

if the average annual regional rainfall increased or decreased by 10

centimeters? How does converting a rain forest or a desert to agricultural land change that ecosystem? 

8. Application: Direct the group’s attention to the United States urban

lights image. Apply skills to identify, analyze, and classify the similarities and differences between global and North American urban development patterns. Q. What variables would government managers use

in remote sensing imagery to plan for new highways, shopping centers, and industry?

9. Self-Assessment: Brainstorm, construct, and present your hypothesis

about regional ecosystem changes on human populations. Q. As you

listened to other group presentations, did any of your assumptions

change about humans’ role in affecting the Earth system? If you were

an Earth system scientist, what technological tools would you recommend for the economic and societal benefit to your community? 

10. http://esto.nasa.gov Download in JPEG or PDF, print, and tape onto

the wall or ink-board, 18 color pages of 8.5 x 11-inch panels of this

lithograph in poster form for further interdisciplinary discussions of the

relationship between urban growth and our “Home Planet.” The

enlarged print forms a 4 x 8-foot wall mural for the students to assemble. Answers to the questions are provided on the Web page.
Module 2, Investigation 1: Figure 2

United States at night map

Module 2, Investigation 1: Figure 5

United States relief map
Module 2, Investigation 1: Log 1

Where do we choose to live and why?

Directions

Apply the spatial distribution concepts to Figure 1 to answer the following questions. 

Questions

1. During what time of the day was this image taken?

2. Do you think this image was taken from the ground, airplane, or space?

3. What do the areas of light on the image indicate?

4. What do the areas of dark on the image indicate?

5. Are the areas of light equally dispersed?

6. Do you see any patterns? If so, identify them.

7. Use a U.S. road map or atlas to: 

• identify and label specific cities, water bodies, roads, or other specific features; and 

• identify which part of the United States this image represents.

Figure 1
Module 2, Investigation 1: Log 2

Where do we choose to live and why?

Background 

In Part B of this investigation, you will apply what you learned in Part A to assemble the segments of a “United States at night”

image and answer questions regarding spatial distribution. Figure 1, in Log 1, shows the northeast section of the United States as

seen at night from space. The image is a compilation of satellite images taken over several months (231 Earth orbits from October

1994 to March 1995) to avoid cloud cover. The white areas are lights, and the black areas are either an absence of lights over land or

over bodies of water. Where there are lots of lights, there are lots of people. People choose to live where they do because of many

factors. People tend to live where it is easy to make a living, is easy to get resources, it is not too wet or dry, it is not too cold or hot,

and the land is not too rugged. 

Procedures 

1. Figure 2 is a complete “United States at night” image separated into eight random segments creating a puzzle. Following the

directions below, assemble these segments to make an accurate image of the 48 contiguous states of the United States.

2. Assemble the segments of the image into the complete map of the United States by connecting features and patterns. Rely on

your mental map of the United States to complete this task.

3. Lay an overhead transparency over the assembled image. Use this transparency and overhead markers to trace the map and

complete the questions below.

4. Use a U.S. shaded relief map (Figure 5) and a U.S. road map or atlas to help answer the questions below.

Section One

1. What region(s) has/have the highest concentration of light? Why? Label these areas.

2. Identify and label the fingerlike areas of dark in the northeast section of the image. Why are they dark? 

3. Identify and label the black region in the southern section. What are the smaller light areas located within this region?

4. Identify and label the area in the western region that is mostly dark. Why is it that way? 

5. Locate and label where you live on the image. Is it in an area of light or dark?
Module 2, Investigation 1: Log 2.2

Where do we choose to live and why?

Section Two

6. Identify and label the 10 areas with the highest density of light. Use a road map to identify them. 

7. Why do areas along coastlines, rivers, and lakes appear to have a relatively higher density of light?

8. Identify and label any major highways you can observe on the image. 

9. Identify and label any major water bodies you can observe on the image.

Section Three 

10. Describe the dispersion of population in the United States.

11. Identify and label any patterns you observe on the image.

12. Does the climate have any effect on the settlement patterns observed in the image? How?

13. Do elevation and relief have any effect on the settlement patterns observed in the image? How?
1. Washington, DC

2. Seattle, Washington

3. Reno, Nevada

4. Denver, Colorado

5. Kansas City, Kansas

6. Detroit, Michigan

7. San Antonio, Texas

8. Miami, Florida

9. Fairbanks, Alaska

10. Anchorage, Alaska

11. Mexico City, Mexico

12. Panama City, Panama

13. San Juan, Dominican Republic

14. Caracas, Venezuela

15. Bogata, Columbia

16. Salvador, Brazil

17. Rio de Janeiro, Brazil

18. Buenos Aires, Argentina

19. Santiago, Chile

20. Punta Arenas, Chile

21. Montreal, Quebec

22. Hammerfest, Norway

23. Lisbon, Portugal

24. Freetown, Sierra Leone

25. Molabo, Cameroon

26. Johannesburg, South Africa

27. Harer, Ethiopia

28. Warsaw, Poland

29. Cairo, Egypt

30. Helsinki, Finland

31. Moscow, Russia

32. Novosibirsk, Russia

33. Vladivostok, Russia

34. Tokyo, Japan

35. Seoul, South Korea

36. Nikolayevsk, Russia

37. Taipei, Taiwan

38. Hong Kong, China

39. Hanoi, Vietnam

40. Beijing, China

41. Ahmadabad, India

42. Almaty, Kazakhstan

43. Singapore, Malasia

44. Paupau New Guinea

45. Perth, Australia

46. Melborne, Australia

47. Sydney, Australia

48. Suva, Fiji

49. Wellington, New Zealand

50. Honolulu, Hawaii

Night Lights of Urban City Development

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