How Much Would It Cost to Build a Real-Life 'Death Star'?

As Star Wars lovers are rejoicing over Episode 1 making it to theaters again in 3D, economics students at Lehigh University are bringing another interesting concept to the Galactic Empire scene. They set out to estimate how long -- and how much -- it would take to create the ultimate planet-destroying weapon: the Death Star.

The students report in Centives that the first Death Star -- you may remember that in Star Wars Episode IV: A New Hope the original was destroyed -- was reported to be 140 km (86.8 miles) in diameter and made of steel. They decided to make the star the density of a modern warship since "they're both essentially floating weapons platforms".

Here's what they reasoned:

Scaling up to the Death Star, this is about 1.08x10¹⁵ tonnes of steel. 1 with fifteen zeros.

Which seems like a colossal mass but we've calculated that from the iron in the earth, you could make just over 2 billion Death Stars. You see the Earth's crust may have a limited amount of iron, but the core is mostly our favourite metal and is both very big and very dense, and it's from here that most of our death-star iron would come.

But, before you go off to start building your apocalyptic weapon, do bear in mind two things. Firstly, the two billion death stars is mostly from the Earth's core which we would all really rather you didn't remove. And secondly, at today's rate of steel production (1.3 billion tonnes annually), it would take 833,315 years to produce enough steel to begin work. So once someone notices what you're up to, you have to fend them off for 800 millennia before you have a chance to fight back.

In addition to the more than 800,000 years of steel making plus man-power to construct the weaponized space station after that, how about the cost (at 2012 prices)? It would rack up a price tag of $852,000,000,000,000,000, which Centives says is 13,000 times the world's GDP.

[H/T CNET]