Experience this giant-sized solar science experiment! Simply fill with air by running, tie off the ends, and let the solar energy of the sun heat the air inside the tube. Within about five minutes, the tube (which must be tethered with string) will rise into the sky. While amazing to see, it also teaches students scientific principles such as density and buoyancy. The thin, black plastic tube holds over 200 cubic feet of air. A complete set of instructions and a number of classroom activity worksheets are included with the solar balloon.