Top Down Background Page



Contents of This Page:

Introduction:
The National Aeronautics and Space Administration, because of its mandate, has a unique way of viewing the earth. The office at NASA Headquarters responsible for actually studying our planet is called the Office of the Earth Science Enterprise (OESE). The perspective of OESEE is to use technology and instrument platforms, be they satellites or aircraft, to gather vast amounts of data without without physically touching the Earth. This is called remote sensing.

The data so gathered are used to infer information about how the mechanisms and processes of the earth system work. Judicious surface observations (ground truthing) are carried out to verify the inferences. In this way local-to-global studies are done, but they are unique because only rarely are measurements made on the ground. And, the perspective is from above, the top, down to the surface of the earth.

In proposing this project, the Project Group (see title page) had one major question: Can the biosphere (that part of our planet where life is found) be viewed pedagogically from space down to the surface using lessons, designed for grade-school students, to teach children about the earth system? The answer was thought to be "yes" especially if teachers were involved in writing the lessons. This Web Site contains a 22-lesson package written by local teachers with the advise and help of Ames Research Center (ARC) personnel in Earth Sciences. The teachers selected to work on this project were recruited through the Bay Area Earth Science Institute (BAESI), an NSF-sponsored program based at San Jose State University. The eight teachers who wrote lessons for the Top Down Project are listed in the table below.


Table 1. List of teachers who wrote lessons for the Top Down Project.

Linda Bull

Miller Junior High School, San Jose, California

Susan Cassidy

Cesar Chavez Academy, East Palo Alto, California

Kathleen Cohen

Miller Junior High School, San Jose, California

Brenda Hough

San Anselmo Elementary School, San Jose, California

James McDonald

Monte Gardens Elementary School, Concord, California

Ursula Sexton

Green Valley Elementary School, San Ramon, California

Sue Van Stee

Youth Science Institute, San Jose, California

Margaret Young

Hayes Elementary School, San Jose, California



Lesson Organization:
The twenty-two lessons that have been written were fit into seven different topical modules. A diagram of the modules is shown in Figure 1 below.


Figure 1. Top Down Project conceptual scheme.

While each lesson and each module may be used separately and generally stands alone, students without a remote sensing understanding should start with one or more of the lessons devoted to the electromagnetic spectrum (EMS). Then students should do the lesson devoted to 2-dimensional and 3-dimensional perception. A lesson on maps and topography should follow and then students should study the concept of scale.

The teachers who wrote the lessons in this package were greatly intrigued by remote sensing. As such, they wrote a number of lessons that deal with aspects of that discipline. In order to understand what one sees in a remotely sensed image, one needs (in part) to know what features on the ground are or were alive and what features never were alive; this is the difference between biotic and abiotic one of the modules in the package. The last module deals with landscape change.



Project Purpose:
Many students are not exposed directly to the concept of an ecosystem or the biosphere until they study individual organisms. The organism under study may be in a jar or aquarium, but it is certainly not in its natural habitat. Students are usually guided to extrapolate from the jar and the organism(s) contained therein to the biosphere. This pathway leads to an incomplete and often flawed view of the world, a view of the world made up of parts that are not connected in any particular fashion. This means that students do not often appreciate that change in one part of the biosphere, be it a hurricane or an excavation for a parking garage, causes change in other parts of the biosphere. Also, students are left with the impression that perturbations of the biosphere can be thrown away and a new biosphere can be manufactured by the next class period.

The Project Team thought that by presenting the study of the biosphere as a whole, from the top down, using remote sensing technology, students would perceive the biosphere as containing interlinked environments and organisms. This structure, the team expected, would aid students when they are introduced later to concepts like, for example, trophic levels and energy flow within an ecosystem and in the biosphere.

It was also expected that students would learn the elements of the physics involved in remote sensing, the ideas of measuring things from a distance, the difference between two and three dimensional representation, and all the ideas and concepts the lesson authors specify in their exercises.



Project History:
The Top Down Project was funded by NASA initially for a single year of module and lesson development. The first year was devoted to selecting the teachers who were to write the lessons and then presenting the teachers with enough information about the project and remote sensing for them to write. Several meetings between NASA personnel and the teachers were held at NASA's Ames Research Center during the first year. Numerous telephone conversations and exchange of faxes also took place in the first year. Because of a delay in funding for the first year from NASA Headquarters, the teachers were unable to complete their writing assignments and test their products in their classrooms. (The teachers who wrote lessons for this project were paid a stipend for their efforts.)

This package of lessons is a work in progress and we would like your feedback! Only a few of the lessons have been tested and these only by the teachers who wrote them. The teachers came from the San Francisco area of California (see the table above) and so the lessons reflect their perspective. Teachers in other parts of the country will have to modify the lessons, where appropriate, to make them applicable to their states and cities and we would like to know about your efforts (see the contact information below). We would especially like snap shots of your students working on Top Down lessons. If time and space permit, we will periodically place selected photos in this package. (All photos should be accompanied by a signed statement releasing the photo contents for NASA use. Credit will be given to the photographer and teacher(s) who submit the photos.)



Module Use Recommendations:
As mentioned above, the lessons in the modules can be used generally in any order, but the team recommends a sequence as diagrammed in Figure 1.

The lessons were written by teachers for teachers, so many contain instructions about advance preparation and planning that must be done before the students are given the tasks to perform. Teachers with motivated students may wish to have those students download the lessons and work directly from the computer.

The lessons are not a specific set of instructions, but rather are guidelines to be used and modified as needed by each teacher to fit into unique classrooms. It is up to each teacher to use these lessons at appropriate places in their school's curriculum.

Disclaimer

Contact Information:

Dr. Jay Skiles
Research Scientist
Ecosystem Science and Technology Branch
Mail Stop 239-20
NASA Ames Research Center
Moffett Field, California 94035-1000
fax: 650/604-1088
e-mail: jskiles@mail.arc.nasa.gov

(this page last modified 09.28.00)


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