On May 25th, 1977, a new movie took theaters by storm. STAR WARS, which revived the scifi space opera genre for movie goers was, according to some, a brilliant pastiche of things loved by people in movies. Next week that movie will reach the 40-year mark since its initial release. While the movie itself has gone through multiple recuts, re-releases, special edition makeovers, and general changes, the core of the film has stayed essentially the same. Even now the movie is quoted and new films are released into the series’ canon of films.
While you may or may not enjoy the film, in its initial release there was a tense moment where a planet is destroyed with a single shot from the Death Star space station. At the time, this scene was amazing and the full strength of the Empire became apparent. But just how much power was needed for this to work, and is a space station capable of such a thing? The short answer is: not without a power plant that doesn’t exist.
How Much Power Do You Need?
There’s an interesting article written by Randall Munroe of XKCD about whether or not you can light up the moon with laser pointers. I’ll be borrowing some information from this article so, while it’s a great read, let me summarize it for you. If you take the most powerful laser on earth, a 500-terawatt laser used for fusion torch experiments, and focused enough of them for a beam diameter as is used by the Death Star, you’d be able to carve through solid moon-rock at roughly 4 meters per second.
Of course, in the article the surface of the moon turns into a plasma rocket so we should assume that something else manages to prevent Alderaan from becoming an interstellar spaceship. That’s still a lot of energy required to only punch a very slow bore-hole into the planet. To reach the center of the planet (assuming that Alderaan is roughly Earth-sized) you’d need a very focused beam on the order of 2 PetaWatts, that is somehow removing the resulting plasma as the laser descends, to carve a hole within the span of a second. But the planet still isn’t destroyed at this point.
Of course, the center of the planet is likely very hot already. But if the laser is powerful enough to reach the core, we can assume that it’s strong enough to turn the inside of the planet into a plasma or exert enough pressure on the core to increase the planet’s rotation, eventually spinning it into oblivion.
The most powerful energy plant on Earth is the Three Gorges hydroelectric plant. It produces roughly 22,500 MW of power. It would take just under 90,000 of these plants to produce a single shot from the Death Star. Which is, of course, why the Death Star uses a fictional hypermatter reactor. Because, in addition to the energy required by the station’s main weapon, you’re also still powering a structure that’s the size of a moon and trying to regulate temperatures inside the station.
Of course, you only need to fire the weapon once, and for a very short time. Nuclear reactions in power plants give off an amazing amount of energy and, by supplementing that energy with stored batteries you could deliver a pulse that unleashes all of the stored energy at once, as the Sandia Lightning Facility does for research into lightning strikes.
