Module 1: Perspectives

January 22 - February 3

In this module, we develop an overview of Comparative Planetology, including the formation of our Solar System, a catalog of its known worlds, and the National Science Education Standards.


Introduction & Perspective:

It helps to have an overall perspective to understand our Solar System - to know what it is, it helps to know what it's not. First, get an idea of the Universe as a whole - I usually think of scales of Universe (the whole thing, oldest, began with Big Bang), Galaxy (ours is the Milky Way, contains star-forming nebulae as well as all the individual stars we see at night), and Solar System (less than half the age of Universe, just Sun and a few trivial things in its influence, formed from collapsed swirling disk). It's easy to dismiss the grand scales as too huge to contemplate, but if you can understand that there are orders of magnitude of these enormities, you can sort things into their proper scales. In general, the spaces between things are vast compared to the sizes of the things - sometimes difficult to imagine, but important to have as part of your thinking.

I like to use 3 frameworks for understanding the Solar System: what's in it, how are things arranged, and how did they get that way? What's in it, in brief: one star (most important), 4 giant (mushy) planets, 4 spherical rocky planets and a whole bunch of smaller rocky worlds (asteroids), some large number of icy worlds (most of the bit ones orbit the giant planets), and some gas and dust. Arrangement: orbits, either around Sun or around other bodies (including double worlds clearly orbiting each other), most are pretty round, mostly in a plane, mostly going 'round counterclockwise as viewed from north.

Formation overview: There was a cloud of gas & dust in space, going 'round the Galaxy. Probably due to one or more supernovae going off, the cloud became unstable and started collapsing to swirling disks, probably in multiple places. One swirling disk became our Solar System. Most of the stuff swirled to the center, where it eventually became part of the Sun. Meanwhile, the solid bits (dust) were colliding and sticking to each other, clumping up, forming larger and larger clumps. These eventually became the worlds in the Solar System. The giant planets may have been formed in sub-swirls within the disk. Meanwhile, back at the center, fusion started in the middle of the forming Sun, and eventually the energy made its way out - Sun started shining. This light (and expanding "exosphere" - aka solar wind) pushed most of the remaining tiny bits & pieces out of the system.

Tools & workings of science: Astronomy is mostly an observational science. That's different from school chemistry or (mostly) biology, in that the only experiments we can do are with models, not usually the real things. Most of the time, we "observe" - but that's not a passive activity. People get very creative about how to observe in order to figure out what they want to learn! Because the Solar System as a whole and most of the things in it are very complex systems (you just can't control the variables, even if you could do experiments), we use models to codify and test our ideas. I don't particularly mean physical models - these models are ideas, and constructions in materials or computers that represent those ideas. We have ideas and models about learning and good science teaching, too. The main tenets of the National Science Education Standards include, significantly, the Unifying Concepts and Processes. Science teaching should stress these, in order to help our students learn the connections among sciences, even the ones we're not teaching them this year.

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Assigned Readings:

Chapter 1, Perspective:

Study Figs 1.1 & 1.3 Don't get bogged down in the details of the walking tour.

Chapter 8, Formation:

Read 8.1-5. Be prepared to return to this chapter in future modules, too.

National Science Education Standards:

Sections 6A, 6B (Read the beginning of 6B, and then read the content standards for your grade level.)

Chapter 3:

Read 3.4, skim the rest of the chapter.

About Names

Links to Internet Readings:

About Names

National Science Education Standards - Section 6A

National Science Education Standards - Section 6B

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Study Questions and Problems:

Answers due at the end of the first week of the module

1. Use the condensation sequence to explain why Earth is chemically different from Saturn.

2. How does the learning of new science by our civilization (the nature of a scientific theory, for example) compare to the learning and teaching of science?

3. List the Unifying Concepts & Processes from the National Science Education Standards (NSES). Briefly describe each one.

4. If a cloud of gas weren't spinning (a very big "if"!) and contracted gravitationally, it would become roughly spherical. What would be the resulting shape if the gas cloud were initially spinning?

5. How did the protoplanets acquire their early internal thermal energy? (Ignore any radiation from stars.)


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Assigned Individual & Team Activities:

Due at the end of the second week of the module

Individual Activities:

Observing Images of the Solar System

Build a Scale Model of the Solar System

Installing Image Software & Image Tutorials

  • Do Remote Sensing & Digital Numbers ONLY - Submit results for Digital Numbers only

Choosing a World

Online Textbook Support (suggested but optional)

  • Register & view Chapter 8 animation on formation of the solar system

Discuss ALL Individual Activities in Team Conferences - Please offer support for each other

Team Activity:

After individuals complete the Observing Images classification activity, team members should share their classification schemes and decide as a group how these images are best sorted. Each member of the group should turn in a short paragraph about how the group decided to sort the images and how the method differed from, or was similar to, their scheme.


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1. Read the assigned readings during the first week of the module.

2. Contribute to the main discussion, which focuses on the readings and the two discussion questions. Other issues (such as the homework) are also appropriate to discuss here. Two posts required PER WEEK.

3. Contribute to your group's discussion. Most modules will have specific groupwork; this first module does not require a group submission, however. The group conferences are a good place to discuss the activities. You will need to discuss your image sorting with your group -- since one of the tasks is to describe your sorting criteria so that others can duplicate it and to decide on a group criteria. Three posts required PER WEEK.

NOTE: HALF the grade for each module is determined by discussion participation!

4. By the end of the module's first week, put your answers to the study questions into an e-mail message and send to "HW Submissions" (without the quotes). Please do not attach a file - simply type or paste the text into the body of the message. It is more than okay to discuss these in your team conference during the first week of each module.

Sometime after this, sample answers will be posted. Review them, and use it as an opportunity to clear up anything you don't understand. Note that it is sufficient to put only your answers in the e-mail, as long as they are identified by number. Please DO NOT use an attachment for your answers; it is much more efficient for us to be able to "reply" with comments to a direct message. If you attach anything that can reasonably be pasted into a message, we ignore it and you get a zero for that assignment.

5. By the end of the module's second week, put your homework into an e-mail message and send it to "HW Submissions". It should contain:

  • Results of your image-sorting - how you sorted the images, how your group sorted them (brief paragraph)
  • Results of your scale model.
  • Sign up for a world by posting your first, second, and third choice to the Module 1 conference. (It is necessary to specify alternative choices because two or more people may be online at once, and sometimes it takes a short time between the time you send a message and the time it shows up.) Please also indicate why you think your first choice is interesting - why you want to study it further. We will keep a list of what worlds are already claimed, and update it as frequently as reasonable. If you want to make trades, please use the Worlds Cafe to discuss the possibilities.
  • Answers to the Digital Pictures Image Processing Tutorial - submit on the website to the instructor. Note - you may wish to submit duplicate answers in a post to the Homework folder on MSU Link.
  • There is nothing to turn in for the installation of the Image Processing Software - you won't be able to do the tutorials if you aren't successful.
  • There is nothing to turn in for the online textbook support registration and animation viewing other than letting us know if you had problems accessing this site.

Sample answers will be posted to Module 1 shortly thereafter. If there are questions, please continue using the module 1 conference to discuss them.

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Discussion Questions

These questions are to be discussed in the Module 1 Conference Folder

Initial Questions:

1. Describe your view of our Solar System. How do you think your students view our Solar System?

2. How might the Unifying Concepts and Processes relate to Comparative Planetology?

Supplementary Questions:

1. Which planet, of the traditional 9, fits least well with the general chemical and orbital properties of our Solar System? Justify your answer.

2. Which of the concepts related to space science do you feel are well covered by the standards and which of the concepts do you believe are no addressed well? What suggestions would you have for revising or interpreting these standards?

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last updated 1/21/02