IMSO 2005 Science International — Experiment Question 2

Experiment 2 — Distance of Planet (20 points)

Basic concept: The small shift in the observed position of a planet when viewed from two separated sites, positions 1 and 2, can be used to calculate the distance of the planet from Earth.

Purpose: To determine distance of planet.

Materials: Telescope; scale; artificial planets (Mars, Jupiter, Saturn). Planet Mars, Jupiter and Saturn are located at certain distances from you.

Procedure — For observing Mars:


**1.** Stand at a fixed distance on position 1.


**2.** Using the telescope, look at planet Mars, and then adjust the focus of the telescope to obtain a sharp image of Mars. Adjust the telescope such that the image is at the center of your view. Without moving the telescope, write down the scale.


**3.** Move to position 2.


**4.** Repeat step 2.

For observing Jupiter and Saturn:


**5.** Repeat steps 1 to 4 for Jupiter and Saturn.

Results:

| Planet | Scale viewed from position 1 | Scale viewed from position 2 | Scale difference |
| --- | --- | --- | --- |
| Planet Mars | … | … | … |
| Planet Jupiter | … | … | … |
| Planet Saturn | … | … | … |

Write your conclusion(s).