Planetary Icosahedrons
The icosahedron is a 20-sided polyhedron with each side made up of an equilateral triangle. Each vertex is formed by joining five triangle faces together. Ancient Greeks discovered that certain solid objects could be made from flat polygons such as the equilateral triangle and square. A tetrahedron is made from 4 triangles, a cube from six squares, an octahedron from 8 triangles, a dodecahedron from 12 pentagons and the icosahedron from 20 triangles. As the number of faces increases in the polyhedron, its shape becomes more spherical.

Each face of the planetary Icosahedron displays a part of the (nearly spherical) planetary surfaces. The triangles are folded so that adjacent triangles are joined exactly at their closest edges. The cut-out pattern forms the complete globe with the North and South Poles at opposite vertices. The overall size of an assembled globe is approximately 2.75 inches if printed on an 8 1/2 x 11 piece of paper and 3.75 inches if printed on an 8 1/2 x 14 page.

To assemble the icoshedron cut along the edges of the map. You can use tape or glue to assemble the globe. Double-sided tape works well. The challenge is in connecting the last edges together. Good luck and have fun.

All of these icosahedrons are © copyrighted 1998-2002 by Calvin J. Hamilton. Permission is granted for teachers to use the planetary icosahedron in classroom activities. Teachers may make copies for their students as long as the copies are given freely to them. Under no circumstance may the icosahedrons be used for-profit or commercial use without contacting Calvin J. Hamilton. The Idea for creating this page was by A. Tayfun Oner.

 Sun Icosahedron The Sun is the most prominent feature in our solar system. The map used to create this icosahedron was made from SOHO images of the sun. Mercury Icosahedron Mercury is the closest planet to the Sun. The map used to create this icosahedron was made Mariner 10 images of Mercury. Venus Icosahedrons Venus is the 2nd planet from the Sun. It is scorched with a surface temperature of about 482° C (900° F) and is veiled by thick swirling cloud cover. This icosahedron was created from a mosaic of radar data taken by the Magellan and Pioneer spacecrafts. Earth Icosahedron Earth is the 3rd planet from the Sun and is the one we appreciate the most since it is the planet we live on. The Earth map used to create this icosahedron was made by A. Tayfun Oner. The land portion of the icosahedron comes from AVHRR data. Moon Icosahedron The Moon is the closest neighbor to the planet Earth. Mars Icosahedron Mars is the 4th planet from the Sun. This icosahedron was created from a mosaic of images taken by the Viking spacecrafts. Jupiter Icosahedron Jupiter is the 5th planet from the Sun. This icosahedron was created from a mosaic of images taken by the Voyager spacecrafts. Callisto Icosahedron Callisto is the second largest moon of Jupiter, the third largest in the solar system, and is about the same size as Mercury. Callisto is the most heavily cratered satellite in the solar system. Its crust is very ancient and dates back 4 billion years, just shortly after the solar system was formed. Ganymede Icosahedron Ganymede is the largest moon of Jupiter and is the largest in our solar system with a diameter of 5,262 km (3,280 miles). It has had a complex geological histroy. It has mountains, valleys, craters and lava flows. Ganymede is mottled by both light and dark regions. It is heavily cratered especially in the dark regions implying ancient origin. Neptune Icosahedron Neptune is the outermost planet of the gas giants. It has an equatorial diameter of 49,500 kilometers (30,760 miles).