Hi CallB and boo,
That’s a good question. And really there’s a lot of factors in that. In terms of our galaxy, the sun probably would expand for another 5 billion years, so that’s a good thing. But there are many other things which could happen, some kind of super virus, an asteroid, all our food dying out because of pollution or us destroying animals habitats. I hope that we are smart enough to 1. come up with solutions to problems as they come along and 2. work together. Who knows!