There are two popular misconceptions about how explosions work in space. The first is the kind you see in sci-fi movies, a giant explosion when a spaceship blows up, often big enough to destroy other ships with the shock wave. The second, believed by many is that because there is no oxygen in the vacuum of space, explosions are categorically impossible .
The reality is somewhere in the middle. The latter
misconception is predicated on the idea of setting fires in
a literal vacuum, wherein you are in the vacuum of space and
trying to flick a lighter on. That would not work, but if
an explosion were to occur inside a spaceship, the oxygen
inside could briefly mix with other gases and form the
necessary chemical reactions for a fire. Depending on the
gas concentrations, it could even be large enough to blow up
a ship. Since there is no pressure in space, the explosion
would dissipate in a matter of milliseconds once it hit the
vacuum. If you blinked, you’d miss it. There would also be
no shock wave, which is the deadliest part of an explosion
in the Earth’s atmosphere.