The “page setup” for your computer’s printer has a “scale.” Use it to scale the pictures so that Saturn with rings must be printed on six sheets of cardboard stock (upper left, upper center, upper right, lower left, lower center, lower right), Jupiter printed on four, and all the rest on single pieces. The smaller ones, such as the moon, Pluto, and Ceres, will be tiny circles in a black field. Many of the Internet pictures have planets with their satellites nearby casting shadows. Use such pictures, if you find them. If you plan to use the pictures repeatedly, cover them with transparent adhesive shelf covering. You may have to stiffen the two larger pictures.

You cannot make a cardboard model of the sun on this scale, but you can put a nice-looking picture on a sheet of cardboard and then make a cord 41.7 feet (12.7 meters) long that can be formed into a circle with a diameter of 13.3 ft (4.04 m) to show how enormous the sun is.

Here are the relative diameters: Mercury (0.56 inch or 1.42 cm); Venus (1.38; 3.50); Earth (1.46; 3.71); Moon (0.40; 1.02); Mars (0.78; 1.98); Ceres (0.11; 0.28); Jupiter (16.00; 40.64); Saturn (the planet is13.33 in. or 33.86 cm; rings make it much bigger); Uranus (5.80; 14.73); Neptune (5.64; 14.33); Pluto (0.27; 0.69).

These make a fine classroom demonstration to compare planetary sizes. You can get all the planets except Jupiter and Saturn on a single sheet of paper if you are willing to overlap Neptune and Uranus and clip the latter two a little. I hand these out with a list of planetary data using the Almanac as my source. It isn’t hard to find these numbers elsewhere.

If possible, mount your pictures on wooden laths (easier to staple than dowels) and take the class outside to see the solar system laid out to scale. I do this by having a reel of string for each planet and having two or three students walk off the appropriate distance for each, unwinding their string as they go. Then they stick their laths in the ground. Take the string from the earth to the sun, and halve it three times to obtain a loop of string one-eighth the original distance. Point out that it takes light a full minute to go this distance!

Here are some relative distances for the planetary orbits (string lengths). You could, of course use your own scale to fit a larger field or a smaller indoor space. Mercury (3.7 feet or 1.13 meters); Venus (7.1; 2.16); Earth (9.8; 2.99; the moon on this scale is only 0.32 inch or 0.81 cm) from Earth); Mars (14.9; 4.54); Ceres (27.5; 8.38); Jupiter (51.1; 15.6); Saturn (94.1; 28.7); Uranus (188.5; 57.5); Neptune (300; 91.4); Pluto (374; 114). The orbit of Pluto is so eccentric that you can avoid that long, long roll of string and simply post the picture of Pluto on a wall or tree well beyond Neptune.

I have done this successfully with children from 9 to 13 years old. The younger ones need help with the longer strings.

Have fun!

.education-world.com/a_tsl/archives/00-1/lesson0069.shtml

Models of compound structures, DNA structure etc.