# How To Destroy A Galaxy

Destroying a Planet

Now we’re talking. The plans for the Death Star might have been stolen, but it’s now able to destroy an entire planet in a split second, as seen in A New Hope. In order to completely eradicate a terrestrial world, you would need the superlaser to overcome something called the “gravitational binding energy.”

This describes the minimum value a spherical, uniform object needs to keep together under the influence of gravity. If this value is exceeded by another energy source, it would tear the planet apart.

Planets are never uniform in terms of their composition, but let’s assume that they are for now. The Death Star decides that Trump isn’t worth the risk, and moves into position over Earth.

Using the mass of the planet, the gravitational constant, and its radius, we can use another lovely equation to calculate Earth’s gravitational binding energy. Turns out it’s 2.3 x 1032 joules, which is about 0.51 billion dinosaur-killing asteroid impacts.

That, dear readers, is how powerful the final Death Star was shortly before it was destroyed by the Rebel Alliance.

Destroying a Star

Scary times. Star Wars via YouTube

Let’s just say that Luke Skywalker messed up, missed that vital thermal exhaust port with his proton torpedoes, and the Empire destroyed the Rebel base on Yavin IV. Oopsies. The Empire then proceeds to upgrade the Death Star even more so that it can unbind a main sequence star, like our own Sun.

According to a complex mathematical concept known as “virial theorem”, a star’s gravitational binding energy is twice that of its internal thermal energy, which can be worked out using yet another similar equation found here.

Our Sun’s binding energy, then, is about 2.3 x 1040 joules, which is 52 quadrillion dinosaur-killing asteroid impact’s worth of energy. In order to unbind our local star – and destabilize and destroy the entire Solar System as a result – the Death Star’s superlaser would need to become 102 million times more powerful.