In zero gravity, a candle’s flame is round and blue!
Fact of Candle’s flame in Zero Gravity
Can a Candle Burn in Zero Gravity?
And answer is YES! but flame is quite a bit different. In zero gravity, a candle’s flame is looking round and blue cause fire behaves differently in space and microgravity than on Earth.
A microgravity flame forms a sphere surrounding the wick. Diffusion feeds the flame with oxygen and allows carbon dioxide to move away from the point of combustion, so the rate of burning is slowed and it is an almost invisible blue color. But video camera can’t detect this blue color.
“But in the microgravity of space, we are not dealing with just another old familiar flame,” says Dr. Vedha Nayagam of NASA’s National Center for Microgravity Research on Fluids and Combustion at the Glenn Research Center (GRC) in Cleveland, OH, where the nature of combustion in space is being studied intently by teams of scientists.
Source: NASA Website