1. Are the objective and introduction written in an engaging way? Yes No     If 'No' please explain. characters left 2. Is the difficulty level accurate? Yes No     If 'No' please explain. characters left 3. Were the materials easily obtained? Yes No     If 'No' please explain. characters left 4. Was the procedure clear? Yes No      If 'No' please explain. characters left 5. Were all safety measures included? Yes No      If 'No' please explain. characters left 6. Did you obtain clear, unambiguous results? Yes No     If 'No' please explain. characters left 7. How much time did you spend on the project? Choose One... A day or less Several days About one week A couple weeks Several weeks to months 8. How much did the project cost? Choose One... Less than $20 $20 - $50 $50 - $100 $100 - $150 $150+ Optional:  Do you have any suggestions to improve this project? characters left Optional:  Attach a picture of your project (JPG, JPEG, GIF, PNG only) Optional:  Caption for picture characters left Thank you for your feedback! * Note: This is an abbreviated project idea, without notes to start your background research or a procedure for how to do the experiment. You can identify abbreviated project ideas by the asterisk at the end of the title. If you want a project idea with full instructions, please pick one without an asterisk. Abstract You can measure the diameter of the Sun (and Moon) with a pinhole and a ruler! All you need to know is some simple geometry and the average distance between the Earth and Sun (or Moon). An easy way to make a pinhole is to cut a square hole (2–3 cm across) in the center of a piece of cardboard. Carefully tape a piece of aluminum foil flat over the hole. Use a sharp pin or needle to poke a tiny hole in the center of the foil. Use the pinhole to project an image of the Sun onto a wall or piece of paper. Use a ruler to measure the diameter of the projected image. Use your knowledge of geometry to prove that you can calculate the diameter of the Sun using the following proportionality: Important Safety Note: Never, ever look directly at the Sun. You can permanently damage your eyes (UC Regents, 2001). Bibliography UC Regents, 2001. "Finding the Size of the Sun and Moon," The Center for Science Education @ Space Sciences Laboratory, University of California, Berkeley [accessed July 31, 2006] http://cse.ssl.berkeley.edu/AtHomeAstronomy/activity_03.html. Variations For more science project ideas in this area of science, see Astronomy Project Ideas. Last edit date: 2010-11-02 09:47:22

I Did This Project! Tell us about your experience with this science project. What was the most important thing you learned? characters left What problems did you encounter? (Enter "none" if you had none.) characters left Can you suggest any improvements or ideas? (Enter "no" if you have none.) characters left How do you rate this project? Poor OK Good Very Good Excellent Optional:  Attach a picture of your project (JPG, JPEG, GIF, PNG only) Optional:  Caption for picture characters left Thank you for your feedback! Related Links Science Fair Project Guide Project Summary Difficulty  5  Time required Short (several days) Share this Project Idea! Donate to Science Buddies Sponsor Sponsored by a generous grant from Northrop Grumman Foundation ECO Classroom: Cultivating the Next Generation of Environmental Stewards A unique field experience for science teachers nationwide www.northropgrumman.com /ecoclassroom/

Career Focus

If you like this project, you might enjoy exploring related careers.

	Astronomer Astronomers think big! They want to understand the entire universe—the nature of the Sun, Moon, planets, stars, galaxies, and everything in between. An astronomer's work can be pure science—gathering and analyzing data from instruments and creating theories about the nature of cosmic objects—or the work can be applied to practical problems in space flight and navigation, or satellite communications.			Mathematician Mathematicians are part of an ancient tradition of searching for patterns, conjecturing, and figuring out truths based on rigorous deduction. Some mathematicians focus on purely theoretical problems, with no obvious or immediate applications, except to advance our understanding of mathematics, while others focus on applied mathematics, where they try to solve problems in economics, business, science, physics, or engineering.

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