Talk in Boulder, Colorado

"The Exploration of the Earth's Magnetosphere"

David P. Stern and Mauricio Peredo

Talk given at the IAGA Assembly in Boulder, Colorado,
Session GA-5.07, Thursday Afternoon, 6 July 1995

We have heard here talks about using the internet for sharing data and scientific information. I now want to discuss a completely different use of the internet--for educating the public, for making it aware of the exploration of space by unmanned satellites.

Books vs. Web Documents

What we have produced here is a general qualitative overview of space physics, the kind of material which could fit a freshman course "space physics for poets." It is still an experiment. Until now the usual way of communicating to the public has been by the printed word: the world-wide web is an entirely new tool, and it is too early to predict how it will work.

A quick comparison:

A book is easy to hold and browse through. You can read while relaxing in an easy chair or in bed, and you need not wait for text or pictures to download.

    But to see it, even only for a quick look, you must go to a bookstore, library or a friend's bookshelf.
    To own it, you must pay money.
    To publish it, you need a publisher, and the process is fairly lengthy and expensive.

A web document is easy to reach and browse through, and it comes free. You can even download it and print it.
It is easily produced on a shoestring budget.
It is potentially more versatile, for instance, it may contain sound and movies, cite other web documents and use internal cross-references.

    But it requires a good computer and network access, which the average person probably does not yet have. The potential audience is therefore smaller.
    The user must sit at a desk, and may have to wait as images are downloaded.

    Which is better? I don't know. One option being seriously considered is to try both routes and make this a printed book as well as a web document.

At the present stage the document is still incomplete. It has almost all of the text--at least, in first draft--but only part of the illustrations, which had unexpected problems. Illustrations are in any case problematic: they are very enticing--much easier to read a picture than 1000 words!--but downloading them takes time, and meanwhile users may lose interest. Our solution so far has been to use small pictures which load quickly, but to include the option of displaying a bigger version, with the user warned in advance about the number of kilobytes involved.

The Material

Here is a list (as of 1995--much was added since) of the main files (+H marks an appended history file):

    Home page (+H)
    The Magnetosphere (+H)
    Magnetic Fields (+H)
    The Polar Aurora (+H)
      Auroral Map of Loomis
      Auroral Map of Fritz
      The Terrella
    Electrons (+H)
    Magnetic Field Lines (+H)
    Electromagnetic Waves
    Plasma (+H)
    Ionosphere... (not yet ready)
    Positive Ions (+H)
    Trapped Radiation (+H)
    Motion of Trapped Radiation (+H)
    Explorers 1 and 3
      The Geiger Counter
    The Radiation Belts (+H)
      Inner Radiation Belt
      Outer Radiation Belt
    Energetic Particles
    Synchronous Orbit
      GOES... (not yet ready)
    The Sun (+H)
      Discovery of Sunspot Cycle
      Discovery of Solar Flares
    The Sun's Corona
    Solar Wind (+H)
    The Magnetopause (+H)
    Earth's Magnetosphere #2
    IMP-8... (not yet ready)
    Lagrangian Points
    The Tail of the Magnetosphere
    Electric Currents from Space (+H)
      The Triad Spacecraft
      The Io Dynamo
    The Polar Caps (+H)
    Auroral acceleration
      Flow direction of electric currents
    Low Polar Orbit
    Auroral Imaging
    Magnetic Storms
    Cosmic Rays
    High Energy Particles (2)
    Solar Energetic Particles

Originally the user arrived at a home page with a brief introduction, linked to concise summaries of various parts, and from there the detailed files could be accessed. Experience has shown that rather than helping, this slowed down and deterred the user. In the final version, the user starts from a "home page" linked to all other files, essentially a table of contents.

The material is completely self-contained, and requires no previous familiarity with science, and no math, because none is used. But it does require time and patience because, as one quickly finds out, there is a lot of ground to cover.


In all subjects we tried to start with the basics. Avoiding technical jargon, we try to define clearly (though often in an intuitive way) concepts such as magnetic fields, field lines, electromagnetic waves, energy and so forth.

And history is used as the general framework. Many files have attached "history files" that tell a more full story, and a tabulated chronology is also provided. Or rather, two tabulated chronologies--one covering the scientific subjects covered in "Exploration," the other embedding the scientific benchmarks in a chronology of society and technology, to clarify the connection between the two sequences.

History is not only important as a framework, it is also where the stories are, adding interest to the exposition. In particular, telling how discoveries came about helps give the non-scientist some of the flavor of the scientist's work, and make clear that a scientist's view of nature is based on careful deduction, not on arbitrary guesswork.


In writing this exposition I tried to emulate two role models. One was Frank Oppenheimer, the founder of the Exploratorium in San Francisco. Oppenheimer's creed was that there was nothing mystical or arcane about science, that a scientist used mainly common sense, just as a farmer would, or a rancher (which Oppenheimer himself was for a while). I know there is a lot of sophistication in the way we use it, but basically that's what science is --applied common sense, bolstered by math.

And the other was Isaac Asimov, the most accomplished popularizer of our era. His popular science books remain eminently readable, and you will find that he always stressed clarity and employed a lot of history.

Intended Audience

Next question--for whom is this material intended? Early on we decided not to aim it at the average citizen, who among other things probably does not have a computer with an internet account. Instead, the material was aimed at the technically inclined and motivated members of society. That is a much smaller group, but they can act as interpreters and pass the word to "casual bystanders" far better than we can.

They include:

    -- Engineers, technicians and others with links to science and technology.
    -- Scientists in non-space fields.
    -- Teachers, especially those of science.
    -- Newspaper writers, members of congress (perhaps!).
    -- People with broad interests that include science and technology, space buffs, science amateurs.
    -- Young people, especially those intrigued by technical subjects.
This exposition is not aimed at space scientists, though they might enjoy it, too, perhaps even learn a thing or two. It could help them explain their work to outsiders--including their spouses and children!


In addition to the material, there are several messages we wanted to get across.

The main one, of course, is that interesting discoveries have been made in space by unmanned satellites, that a whole new world has opened up in the magnetosphere, a whole new range of phenomena.

We want to tell the users that here is one of the frontiers of human knowledge, and it contains many as yet unsolved mysteries. To the extent people are interested in science--and not everyone is, one must admit that--it is this feature which seems to attract them--the novelty, the exploration of the unknown. There is a little bit of the explorer in every one of us, which is why this web document was titled "Exploration of the Magnetosphere."

Another message is that although space physics seems exotic, it is just an application of the same science one learns in school. Science teachers ought to find new relevance for their material, and engineers or technicians may also relate to it.

For example, to illustrate what a plasma is, the operation of a fluorescent tube is described, and later the ballast coil of such a tube is given as an example for storage of energy by a magnetic field.

Still another message is that the exploration of space is an international effort, an adventure shared by all of mankind. Not just Americans but also Swedes, Britons, Norwegians, Japanese, Russians, Germans and others have been deeply involved, and we have tried to give credit to all of them.

    Let me conclude. Nothing I state here can describe "The Exploration of the Magnetosphere" as well as the web document itself, and I encourage you to log on and see for yourselves. It is still incomplete, it certainly needs more polishing and there may even be a few bugs left. By simplifying the lay-out and limiting the illustrations, we made sure that it will load quickly.

And we plan a disk version, perhaps as an add-on freebie on CD-ROMs of space data which have unused disk space. And as noted before, it may also become a book of 150 pages or so.

Let us Hear from You!

What I ask you here, after you have logged on and seen the material (and it may take several sessions!)--please, let us hear from you. Become participants in this project! We need your feedback, we need you to tell us what is good, what is weak, what is missing, what should be cited, and how the material can be made more attractive and useful. Our E-mail addresses are at the end of each web page. Let us hear from you and perhaps, with your help, the word will get out to the wider public.

Last updated 25 November 2001
Re-formatted 9-28-2004