In zero gravity, a candle flame behaves in a completely unexpected way. Instead of forming the familiar yellow, teardrop-shaped flame that rises upward on Earth, the flame becomes a small, blue, floating sphere. This happens because, without gravity, hot gases don’t rise and cold air doesn’t sink—eliminating the convection currents that shape flames on Earth. On our planet, gravity pulls cooler, oxygen-rich air downward while hot combustion gases rise, stretching the flame upward and giving it a