S k y   l a n t e r n s  &  S o l a r   b a l l o o n s 

A hot-air balloon that has been causing nocturnal UFO sightings since the early seventies is the sky lantern. This miniature hot-air balloon is usually made of thin plastic or flame-retardant tissue paper, a bamboo ring at the bottom, and a thin cross-wire that supports a piece of wax-impregnated paper (or anything else that can be ignited and serve to fuel the balloon). Sky lanterns are known by a host of other names, for instance : fire balloons, Chinese lanterns, Thai lanterns, Kong Ming balloons, Khoom Fay balloons and Khoom Loy balloons. They were supposedly invented in China 1800 years ago, as a way of communication between two distant places at war time. In Asian countries, the balloons are released by the thousands at celebrations each year (such as the yearly festivals in Pingsi, Taiwan, and Loi Kratong, Thailand).

They are easy to make at home. All you need is some tape, a garbage bag and a couple of drinking straws or a piece of iron wire to construct the frame that keeps the burner in place. The latter can be a small reservoir with methylated spirit, a candle or just a piece op paper soaked in lamp oil. When aloft, sky lanterns are visible as a red-orange light (the flame) surrounded by a thin halo (the reflection of the flame on the circular frame). They take the appearance of a small blob or ball of light as they climb higher in the sky, to finally become visible as just a red point of light. The lanterns, like all other balloons, move with the air currents, usually in a straight line, but sometimes erratically and changing direction when encountering other air streams. Especially in recent years sky lanterns became immensely popular in the Western world, causing UFO reports on an almost daily basis.

A variant of the hot-air balloon is the solar balloon. Here itís the Sun that heats up air trapped in a closed plastic envelope. Solar balloons are easy to make by joining two or more large black garbage bags together with tape. The dark colour helps to absorb the sunlight more quickly. The most common shape is the cylinder, but many other shapes have been launched successfully. Solar balloons can be many metres long and sometimes reach altitudes of several miles, scaring the living daylights out of unsuspecting airplane pilots.