Part 2C: Model – a Potato as an Asteroid
A. ASTEROID PRIMER (Review)
TEACHERS/LEADERS: The first link below provides the slides from Tyler’s 2018 “Asteroid Day” presentation. The second link has the same questions listed below in a document The third link is the answers to these questions.
- 1. What is the definition of an asteroid?
- 2. What general shape are asteroids? Why?
- 3. What is the current understanding of the origin of asteroids?
- 4. Describe their movement in the solar system.
- 5. What is the difference between these classes of asteroids? (recall the small coding script you made in Section 1 to determine the classification of a few asteroids).
- Near Earth Asteroid (NEA)
- Main Belt asteroid
- Mars crosser
- 6. Compare and contrast the difference between orbital revolution and self rotation (spinning).
- 7. Why do you think an asteroid spins?
- 8. Why are we able to detect light from some asteroids?
B. POTATO MODEL
TEACHERS/LEADERS: Use the link below for a resource with pictures and tips. This is an accessible model. Please modify or add to it as you would like.
STUDENTS:It is helpful to be in a group to make your model.
The following are GENERAL instructions:
- 1. A potato represents the asteroid. Why do you think a potato is a good model for an asteroid? What axis, the length or width, do asteroids generally spin on?
- 2. White map pins will be a tactile representation of the light that is reflected into the telescope from the asteroid.
- a) Place eight clusters of different numbers of pins, at eight positions around the potato, representing the light reflecting into a telescope from a rotating asteroid.
- 3. Spin the potato ⅛ of a turn at a time, each spin representing an observation taken at specific times – for example, each turn could represent images taken 14 minutes apart.
- a) For simplicity, only count the pins in the area defined by the ⅛ turn, even though you may be able to observe more pins.
- b) Collect data for at least two rotations. Why are you collecting data for more than one rotation?
- 4. Plot # of pins vs observation time, with time on the horizontal axis.
- a) Use tactile graph paper if available.
- 5. Analyze curve
- a) Find the period of rotation for your asteroid from the graph. See your teacher or leader for help.
- b) This graphical representation is called a “light curve”.
- 6. How could the information from the curve be communicated in another, non-visual manner?
Use your journal to record the period of rotation of YOUR asteroid. Also, record your ideas for question #6.
In summary, taking images of an asteroid over one night allows a light curve to be plotted. This is because, as the asteroid rotates, it reflects different amounts of sunlight.
Plotting the amount of sunlight reflected by the asteroid on one axis and time on the other will enable us to find how long it takes for one rotation.
This can then helps us find the asteroid’s mass and composition.