Here's what would happen if you lit a firework in space

Without additional oxygen provided by Earth's atmosphere, fireworks wouldn't behave the same way as they do on Earth.

Photo credit: Getty Images

Published: November 4, 2023 at 4:00 pm

In the vacuum of space, there’s no oxygen with which things can burn. Fireworks, however, contain their own oxidiser, which provides the oxygen required for combustion (normally a nitrate compound such as potassium nitrate). 

Most professional firework displays use an electronic igniter system. This sends an electric current through a wire to the firework’s fuse, igniting it, again without the need for oxygen. So, fireworks work perfectly well in space. But you can’t light a firework in the vacuum of space with a flame, as your flame won’t burn.

Although, once lit, a firework’s propellant fuel burns with its own oxidiser, this is not necessarily true for the pellets of material that are used to create the various spectacular effects and colours seen in today’s fireworks. Those combustion reactions, usually using salts of strontium, copper, barium, and so on, generally require additional oxygen, which is normally supplied by Earth’s atmosphere. This means that the colours of fireworks in space would be much less bright and fade much quicker than they would on Earth. 

Another noticeable difference between fireworks on Earth and in space is that space-borne fireworks would make no sound in the vacuum of space. 

On Earth, fireworks reach a limited height due to air resistance and the effects of gravity. In space, however, they would move much faster and further.

On the Moon, for example, a rocket could travel six times as high as on Earth. This would mean the most powerful mortar-launched fireworks could easily reach several kilometres above the Moon’s surface before exploding. So, fireworks for space would need to be designed to explode sooner than on Earth.

So, without a radical redesign, fireworks in space would be silent, brief, almost colourless and far less spectacular than those on Earth. 

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Asked by: John Kilmister, Southampton

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