http://serc.carleton.edu/spaceboston/2011activities/57640.html#discussion http://serc.carleton.edu/spaceboston/2011activities/57640.html#post18343
I'm glad you acknowledge that the crystal measurement is a simplification for your students. It turns out that a lot of the cooling rate calculations were done based also on nickel content of the crystals, beyond what can be done in the classroom.

Please keep updating and be sure to let us know how this goes in the classroom! And let me know if there are specific areas I could help with; on the whole you've got a great activity here.

Lindy]]> Lindy Elkins-Tanton 1313600640 http://serc.carleton.edu/spaceboston/2011activities/57640.html#post18343 http://serc.carleton.edu/spaceboston/2011activities/57640.html#post18345
I like the way you've structured this to begin with general observations of the images, followed with some information and the measurement activity. It sounds engaging. The issue of the nickel content, which can't be determined by kids in the classroom, puts me in mind of a comment Laura (the teacher who visited at the end of the course) made. She noted that she finds herself pointing out and discussing the complexities of the content more, as a way of helping students understand it, rather than trying to make it more clear by oversimplifying. Your activity presents that opportunity. It would be great for kids to be able to read or hear how some particular meteorites were studied and their age determined. (Recommendations for readings, anyone?) Thanks for the extensive background, specific sources, and details about how you will frame this for students. I'll hope to hear more as the school year goes along!

Ellen]]> Ellen Doris 1313756700 http://serc.carleton.edu/spaceboston/2011activities/57640.html#post18345