Sky Lanterns are like mini hot air balloons. They are made of non-flammable, biodegradable material. A wick is suspended from the frame (cross hairs) which is lit enabling the flying lantern to fill with hot air and float off into the sky.
They were invented in China in the 3rd century AD by a military strategist called Zhuge Liang as a way of sending signals. Since that time they’ve grown in popularity and have begun to be used at carnivals throughout the world.