1. The problem statement, all variables and given/known data To what radius do you need to compress Mars in order to turn it into a black hole? 2. Relevant equations None given, but I am mildly familiar with Schwarzschild and his equation. I know that if we double the object's mass, multiply by the universal gravitational constant, and divide the entire thing by the speed of light squared we can technically turn anything into a black hole. In other words: Per the text: R=(2GM)/(c^2) 3. The attempt at a solution Obviously I can plug and chug with the equation, but I want to understand WHY this works, and maybe how to derive the equation (if that's even possible at my current understanding). I am fairly unfamiliar with black hole physics, but my instructor thought this would be an interesting problem for us to solve (currently in electromagnetism/thermo). Thanks!