Is the sun getting smaller (mass) or larger and is it getting hotter or colder?
As the Sun fuses hydrogen into helium, the mass is decreasing but the size is increasing. The Sun is getting hotter. It is 30% hotter now than when it ignited. This process will continue until the Sun reaches Red Giant status in about 5 billion years. However, this is a slow process. One billion years from now the Sun will be another 10% hotter. This will be enough to vaporize all water on our planet and no life forms (not even simple single cell life) will be able to survive in the extreme heat. Two billion years from now, our planet will be nothing more than a burned rock.
