Most things won't burn on Mars—after all, the main ingredient in the Martian atmosphere, carbon dioxide, is used in fire extinguishers on earth. So how would one create fire without oxygen? Use metal!This slow motion footage shows magnesium burning within a block of dry ice. To begin the demonstration, Eric Muller adds magnesium powder into a hollow carved in two blocks of dry ice. He inserts a lit fuse made of magnesium ribbon. Placing the blocks together seals the magnesium from air. The magnesium burns inside the dry ice, producing a beautiful glow. When the fire is out, what remains is white magnesium oxide and black carbon.