The image to the left is what could very well be Oprah's laser cannon. It looks intimidating and has Earth locked on as its target. This cannon would probably be seen from Earth in the summer when Mars is closest. The laser would most likely be powered by a new found martian resource similar to uranium only it would create more energy during a reaction. In short her laser would be powered by the heat of fusion. The process for firing wouldn't be overly complex, first a reaction occurs in chamber one, next the energy is channeled into chamber two and then converted into heat and light, finally it is fired from the front of the cannon and at its target. Seeing as how the laser travels at the speed of light and the distance of Earth and Mars is less than a light year away, 55,746,199 km to be exact, we would have little time to setup a defense. Our only defense would be a giant mirror, which can be read about in the section "Fighting Back". Even if we managed to save ourselves once Oprah would still have the upper hand unless we retaliated.