Burning a Signal Flare on the Moon

Will a signal flare burn on the moon? If so for how long.
- cameron (age 10)
Canada

Sure, a signal flare will burn on the moon, but you have to make a special one. The flare has to have both the material that burns (usually magnesium, which burns very brightly), and oxygen. There are signal flares that burn underwater -- one was recently used very visibly for the 2004 Olympic Torch. A company in Australia made a specially formulated flare which supplies its own oxygen at enough pressure to keep the water out while the flare burns. The pressure may not be much of an issue on the moon (but the oxygen has to be present at a high enough pressure to allow the combustible material to burn). You can even imagine a flare made of a compressed tank of oxygen, a nozzle, and an ordinary flare. These will burn as long as the ordinary flare would burn and the oxygen supply lasts (or may even burn longer if the oxygen is supplied more slowly, but would burn less bright). You can always make one that burns longer by making it bigger, with more combustible materials. Of course you have to arrange it so it doesn’t all burn at once (an explosion). The underwater olympic torch was designed to burn for about 3 minutes underwater.

Tom

(published on 10/22/2007)