with Leigh Ann Yoder
The Goldilocks Principle
Venus is too hot! Mars is too cold! Earth is just right!
In class the students were introduced to the atmospheric differences between the three "sister" planets in a graphic and hands-on way. We began by discussing the greenhouse effect which is the effect of the atmosphere to trap heat. We also discussed the trace gases in our atmosphere known as the greenhouse gases, and how they function much like the glass plates found on a greenhouse used for growing plants.
We used a table to show the percentages of the main atmospheric elements on all three planets. Students then modeled this data using jelly beans. Modeling allowed them to think about a concept that could not be observed directly. After completing the models, we needed to address the effect of atmospheric pressure on our three planets. Earth's atmospheric pressure is 1/90th that of Venus and 100 times that of Mars. Again, by modeling with our jelly beans, students were easily able to understand the concept and its effects.
We discussed that many scientists believe that the composition of our atmosphere is due to the presence of life, and that life creates a dynamic balance. If life were to disappear would our planet come to resemble Mars or Venus?
We finished by creating another table to compare the temperature on the planets if we eliminated the greenhouse gases, and their actual temperatures. Using this table again reinforced the importance of these trace elements in our atmosphere.