: : A friend recently asked me, "What would happen to the Earth if then Sun became a black hole with the same mass as the Sun?" We both agreed that this could not happen to the Sun but he insisted I answer his question. I was not able to. I know that the gravitational force on the Earth would stay the same, but would the lack of the sun cause the Earth's atmosphere to freeze and core to solidify? And if they did, would the the Earth stop rotating and continue its elipsis around the black hole with only the heaviest side facing the black hole? Would the Earth's lack of rotation cause its revolution around the black hole to slowly degrade causing it to eventually fall into the black hole?

: : If anyone can answer any of my questions I would be appreciative.

Actually , I had read from a magazine that if the earth becomes the black hole in case its mass is same with the sun , the event horizon ( the areas of which any object is pulled into the black hole ) is less than 3 km only, but don`t worry the potency of any planet to become the black hole is always depend on the large size , I mean that the planet is bigger than the sun size. Sorry , I can`t answer the latter questions, but I will try to find any information about that.