Here on planet Earth we're used to flames -- whether from a candle or campfire -- reaching upward to the sky with slender limbs hungry for oxygen and driven by rising hot air. But in space, sans our planet's strong gravitational pull, flames are more likely to take the shape of eerie fireballs.
Within the flame of a regular candle wick, there's quite a bit going on. As the video below released this week by NASA explains, molecules from the wick are being cracked apart and vaporized by the flame, then combined with oxygen to produce light, heat, carbon dioxide, and water, as well as soot.
In recent years we've become quite familiar with how flames can extend and expand quickly in their greedy quest for more fuel and oxygen; witness countless western wildfires of the past decade. But researchers aboard the International Space Station have observed that flames in microgravity behave much differently, staying in a small spherical shape and letting oxygen molecules come to them.… Read more