Sure, we’ve all seen it done in everything from Star Wars to Titan A.E. But, speculative Science Fiction and Fantasy aside, how would you go about it? Mind you, I’m not talking about just trashing the biosphere or ending human life. I’m talking about completely obliterating the planet by explosive or other high-energy means. (Completely melting the planet, for instance, is perfectly acceptable.) For the purposes of this discussion, Earth will be our target, since we know it, and presumably its weaknesses, very well. Be advised, however, that whatever method you come up with, other planets may not be like Earth. So if you intend to go on a planet-killing spree, destructive techniques that take advantage of weaknesses like plate tectonics or molten cores are bound to fail when you come up against a planet that doesn’t fit the profile. Still, every journey must start with a single step, so if we can just figure out a way to destroy the Earth, then, technically, our spree will have begun. So how do we do it? Here are the rules: The Moon is our base of operation. It is assumed that any materials used to bring about the Earth’s destruction will be manufactured and on the Moon and delivered (if necessary) from the Moon’s surface. Anything in the solar system (planets and asteroids, for instance) is fair game and available as a resource. (And, yes, the Moon itself is allowable as an expendable “resource” for our diabolical plans.) Keep in mind that such resources must be somehow commandeered from the Moon. The Earth must be destroyed within a year after the plan is devised and set into motion. So no plans are allowed like spending the next 1000 years attaching solar sails to the planet Mercury and then watching it slam into Earth 10,000 years later. No breaking the laws of physics as we currently understand them. Magic is not allowed. The use of any exotic material that can actually exist is allowed. Remember, however, that any materials used will originate on the Moon and must be transported (if necessary) from there. Energy, however, is neither free nor infinite. So while it is assumed that you have the means of manufacturing neutronium projectiles with the mass of mountain ranges (for instance), they won’t do you any good unless you devise a way to transport them out of the Moon’s gravity well and pummel them into the Earth. The methods of delivery must be achievable within the timeframe stipulated. So how about it? Can we destroy a planet, or not?