Scale Model of the Solar System This assignment is the most important assignment that I will give out during the entire course. It is my best effort to give you a sense of the sheer immensity of space and the vast distances between things like planets and stars. I wish that I could be there with you to teach this myself. I wish that the teaching life of Mrs. DeHaven could be easier than it probably is becoming. I also wish that the things that the newest technology has developed would work better than it does here. However, these are only wishes, and the reality is that creating lessons here in China is difficult because the internet continues to work one minute and the next minute it doesn’t.

Scale Model of the Solar System Every student in the 14 years of my teaching has done this project, and it is the best plan that I have seen to help students get an understanding of where the Earth is compared to the Sun and planets, and where the Earth is compared to other stars.

Scale Model of the Solar System In this project, you are going to create a model of the solar system using a round circle to represent the Sun, and then figuring out how big or small the planets are in comparison, and how far away those planets are compared to that “sun.” The project is not difficult, and can be a lot of fun.

Scale Model of the Solar System First … you will need to divide the class into 3 groups. Since there are 6 rows in the class, divide the class into 3 groups of 2 rows each. One person is the recorder. One person is the er. One person helps everyone figure out how the calculations are made … meaing that you need a calculator.

Scale Model of the Solar System Second … you need access to the computer, either now, or at the end of the class, or at some time later in the day. This is so you can send your final results to me. Third … you will need the handout that Mrs. DeHaven has. This is what you are going to fill out in your groups, and later transfer information from that worksheet onto the computer at this address: rses/online/astro/forms/scale_model/scale_m odel.html rses/online/astro/forms/scale_model/scale_m odel.html Okay … it is a long address, but it gives you the place to officially turn in your numbers.

Scale Model of the Solar System You are going to cut out a piece of paper and make a circle that is 20 cm in diameter. This 20 cm circle represents the Sun. (pictures are coming later … so be patient). Now, that 20 cm diameter represents the actual Sun which has a diameter of 1,392,000 km. So, in this scale model, everytime you move 20 cm, you are moving a representative 1,392,000 km in space.

Scale Model of the Solar System This ratio of 1 cm = 1,392,000 km is used for every planet whose diameter you will determine and whose distance from the Sun you will determine. I have given a help sheet to Mrs. DeHaven, so that she is able to help you. Here are two examples to simplify your lives today.

Scale Model of the Solar System Earth Scale Diameter & Distance 20 cm/1,329,000 km = ? cm/12,756 km So … the formula is (20 cm x 12,756 km)/1,392,000 km = scale diameter of Earth. (20 cm x 12,756 km)/1,392,000 km = 0.18 cm … which is 1.8 mm 20 cm/1,329,000 km = ? cm/149,600,000 km So … the formula is (20 cm x 149,600,000 km)/1,392,000 km = scale distance of Earth. (20 cm x 149,600,000 km)/1,392,000 km = 2149 cm which is m So the scale model Earth is a 1.8 millimeter BB that is meters away from a 20 centimeter ball that represents the Sun

Scale Model of the Solar System So … you use the same ratio of: 20 cm/1,329,000 km = scale value cm/known value For every planet diameter and every planet distance. By the time you are done, you will have a mental picture of where the planets are compared to the Sun, and how big the planets are compared to each other and compared to the Sun!

Scale Model of the Solar System The challenge is to determine where the Sun is relative to other stars up in the sky. Remember from a day or so ago, that the Milky Way is an immense collection of 200 billion stars. The Sun is just one of these stars.

Scale Model of the Solar System The challenge is to determine where the Sun is relative to other stars up in the sky. Remember from a day or so ago, that the Milky Way is an immense collection of 200 billion stars. The Sun is just one of these stars. The image to your left gives to a perspective of where the Sun is within the galaxy.

Scale Model of the Solar System The Sun is estimated to be 25,000 light years from the center of the galaxy. So, the Sun is just one of 200 billion, and these stars are all light years of distance apart from each other!

Scale Model of the Solar System The closest star to the Sun, among the 200 billion Milky Way stars, is Proxima Centauri. It is a red star that is very small, and is only visible in the southern hemisphere sky. This little star, whose picture you will see later, is 4.3 light years away from the Sun. 4.3 light YEARS!

Scale Model of the Solar System Do the math for the scale model 300,000 km/sec, 60 sec/minute, 60 minutes/hour, 24 hours/day, and days/year means that light travels 9,467,280,000,000 km in one year. This is very far, but Proxima Centauri is 4.3 of these “light years” away from here. You use the light year distance times the 4.3 years to determine the actual distance to this star, and then plug that value into the formula to figure out the scale distance that Proxima Centauri is from the 20 cm circle! Do the same for Andromeda, except this galaxy is 2,650,000 light year away, so instead of multiplying by 4.3, you multiply by 2,650,000.

Scale Model of the Solar System Once the math is done, plug the numbers from the worksheet into the computer. I will need two things from you here. 1) I need an to me at: with the names of the students in your group. 2) I need the recorder to put the values into the appropriate worksheet space on my online program at: es/online/astro/forms/scale_model/scale_model.html es/online/astro/forms/scale_model/scale_model.html es/online/astro/forms/scale_model/scale_model.html

Scale Model of the Solar System Now … look at the presentation on the next page …

Scale Model of the Solar System The link included in this box will give you a look at the planets in our Solar System so that when you are on your walk, you have a better picture of what things look like. Look at the link as a class … AFTER you finished the math, but BEFORE you go outside! ses/online/astro/forms/scale_model_presentati on/scale_model_present.htm ses/online/astro/forms/scale_model_presentati on/scale_model_present.htm

Scale Model of the Solar System Finally, go outside and take a walk! That’s right … go outside and walk the Solar System! Stick the circle on the school and pace out to as many planets as you can without crossing over Cedar Lake Road. While you are out there, get a sense of where the Earth is, where Uranus is, and where Proxima Centauri might be. Try to stay together in a group!

Scale Model of the Solar System THANKS to you students, and also to you Mrs. DeHaven. This cannot be easy … both sitting in my class while I am in China, or teaching in my absence. I am so thankful for your patience! The to me is worth 25 points for each student on the list, and the completed online scale model form is worth 75 more points for each student on the list.

Scale Model of the Solar System It is Friday here in Beijing as I write this. Tomorrow evening is Opening Ceremonies. Sunday morning, Anna Swims her first race of the meet. By Monday morning in class, you will get to know how she did Sunday morning, Anna Swims her first race of the meet. By Monday morning in class, you will get to know how she did Have a GREAT WEEKEND, Tom