Just last month when Elon Musk from Tesla Motors, said that he wanted to drop nuclear bombs on Mars to get it ready for colonising, he was described as supervillain. He has however clarified that his intention is to launch two huge fusion bombs into the sky above Mars that will explode every few seconds to keep the planet warm enough for humans.
The bombs are intended to act as tiny pulsing suns that would hover over the planet. He said that his intention was to have a series of very large explosion by human standards, but very small by calamity standards, by having two tiny suns over the poles of the planet.
Mars at present is inhospitable because its environment is too thin and cold for humans. A plausible way to make it hospitable is by injecting greenhouse gases in its atmosphere that would make the planet warm. Musk wanted to do so by using two little stars. The stars would warm the planet and turn the frozen carbon dioxide into gas that would support an atmosphere like earth.