Can Spaceships Actually Explode Like They Do In Movies?

There are plenty of things about Hollywood blockbusters that are hard to believe, and with the recent global success of Star Wars: The Force Awakensa popular piece of movie magic has come back into question. When those starships are battling in outer space, shooting lasers in every direction, we see tiny fighters zooming in and around explosions, while unlucky ones catch a stray blast and blow up in dramatic fashion.

It makes for great cinema, but what’s the reality behind it? What would an explosion really look like in space?

Advertisement

A Very Different Type of Explosion

An explosion, as we commonly understand it, is a massive outburst of gas, heat, and pressure by a material when subjected to a certain pressure or temperature. It is essentially a rapid shift from potential energy into work, and on Earth, many explosions are accompanied by a fireball.

That fireball is the real point of contention, because it arises from the burning of flammable gas or liquid, along with oxygen. Fire requires three very simple elements to exist: oxygen, heat, and fuel. This basic list of “ingredients” is why fire is likely the first chemical reaction humans ever experienced, and yet it still fascinated us to this day.

Many people would argue that explosions and fireballs can therefore not exist in space, because it is a vacuum, without oxygen. Therefore, the belief is that fuel and heat may exist in space, but without the requisite oxygen, fire wouldn’t form. The thing is, that isn’t completely true.

An oxidizer is required for a fire to exist, which is actually a broader class of substances. On Earth, the most readily available oxidizer in oxygen, which is why we think a fire “needs” oxygen to survive. However, if a spaceship that has liquid hydrogen and liquid oxygen on board happened to explode, that oxidizer would be able to fill the role and combust with the fuel and heat.

Advertisement

The explosion would look very different, however. The debris from the explosion would be forced outward in every direction from the center of the blast, and continue moving in a straight line without any atmospheric force to stop it. Smoke wouldn’t go “upwards” and fire wouldn’t keep persisting, but the full-speed shrapnel flying in every direction arguably makes explosions even more dangerous in space.

An explosion in space would realistically look like a brief spherical burst of light moving outwards, as well as a discharge of energy and material from the exploding object (energy and light can both travel in a vacuum). For a moment, the area around the exploding ship would no longer be a vacuum, given the outpouring of oxygen from the ship. It would take a moment for the pressure to rebalance from space and for the fuel to be burned up. As soon as any available oxidizer was used up, that would be the end of combustion and consequent “fire”, but the force of the explosion would still be significant.

When it comes to an exploding spaceship, however, most movies miss one important aspect. The explosion would continue forward at the same velocity as the ship was moving, considering that all the ejecta and materials involved in the explosion wouldn’t have any atmospheric force to stop it. This is one detail that most movies skip, typically showing things becoming stationary once they “blow up”.

What About Chemical and Nuclear Explosions?

Chemical explosions are slightly different than physical ones that we are used to seeing in Earth-based movies. Chemical explosions occur by breaking apart weakly bonded chemical components, and no oxygen is required for that type of reaction.

z9lsh

Nuclear explosions have actually been tested quite extensively in space, most famously in the Starfish Prime explosion in 1962. With a yield equivalent to 1.4 megatons of TNT, that nuclear detonation occurred 250 miles above the surface of the planet. That resulted in much more than a “brief” flash of light, and intense auroras from the nuclear explosion could be seen across most of the Pacific region, persisting for as long as 7 minutes.

Similar to chemical explosions, fission reactions don’t require oxygen, but they do create an intense amount of light and energy, and would likely look quite similar to a nuclear explosion on Earth. Think about it this way, our Sun appears to be “on fire”, but is in fact constantly experiencing fusion reactions (the opposite of a fission reaction, which produces a nuclear explosion).

To summarize, explosions can definitely happen in outer space, but they depend entirely on the chemical and physical conditions of what is exploding. Furthermore, most explosions would last for a much shorter duration and would likely be far less dramatic than we see in our typical Hollywood action flicks.

Sorry… didn’t mean to burst your Star Wars bubble!

References

  1. Ask An Astronomers -Cornell University
  2. NASA
  3. TVTropes
The short URL of the present article is: http://sciabc.us/sGHmv
Related Articles



Add comment

E-mail is already registered on the site. Please use the Login form or enter another.

You entered an incorrect username or password

Sorry, you must be logged in to post a comment.

2 comments

by Newest
by Best by Newest by Oldest
1

Hello. And Bye.

2

When watching a space explosion in a motion picture the effect that annoys me most is the planar shockwave http://tvtropes.org/pmwiki/pmwiki.php/Main/PlanarShockwave
One was added to the destruction of the Death Star in Star Wars when George Lucas redid the movie.
It is supposed to represent a wall of out rushing gas. But any wall of gas escaping the ship would be mostly spherical in nature. The planar shockwaveon the other hand is a flat object it seems to be rushing into an already existing substance. The only movie that got this right was Star Trek II the Wrath of Khan. when the spaceship exploded it was in a nebula of dust and gas and the shock wave was spherical. The edge of it was visible like the edge of a soap bubble and was vertical to the plane of the movie screen.
As far as the visible of explosion of fission or fusion bombs in space goes it all depends on whether the bomb is in a spacecraft or floating alone in space. Most of the energy released in a nuclear explosion is in the form of x-rays. On earth the X rays heat the atmosphere producing much of the light we see. The explosion of a nuclear bomb isolated in space would produce a brief strobe like flash followed by an afterglow. If on the other hand the nuclear bomb were to explode inside an Star Wars Imperial Star Destroyer the result would be quite spectacular.