# Sun as our Supergiant

Let's talk about the time when our sun becomes a supergiant. We know that our solar system may get destroyed or it may get affected due the large mass of the supergiant and also due to the large temperature. But somehow let us consider nothing happened to our solar system by luck. It's obvious that life won't be possible on earth anymore(due to the extreme heat), but is there a possibility that, the events that took place during the formation of Earth, may take place in the far off planets? Can life formation take place in some other planet just like it happened in Earth??

• The Sun will never become a supergiant. It will become a red giant, which is much different. Additionally, the mass of the Sun will not increase. Jan 14, 2016 at 21:15

The Goldilocks zone for the possible occurrence of life, uses the criterion of liquid water as the basis for allowing life to evolve. As a star becomes more luminous (and an AGB Sun would probably be about 100 times as luminous as the present Sun), the Goldilocks zone moves outwards roughly proportional to $\sqrt{L}$, so about a factor of 10 further away.
The problem then with allowing life to evolve on another planet (e.g. Mars after its orbit has expanded a bit, or Jupiter) is that (i) you need the ingredients to be there already, or some way for them to be delivered, but more importantly (ii) there is little time for life to evolve, because the Goldilocks zone position evolves really rapidly towards the end of the Sun's life as the AGB Sun's luminosity increases - the timescales would be measured in millions rather than billions of years. Furthermore, the luminosity of AGB stars can be highly variable as they undergo big pulsations, which may also be a problem. (iii) After the (comparatively brief) AGB phase has ended, you would end up with a very hot ($T \simeq 10^{5}$ K) white dwarf remnant that might effectively sterilise the whole system with ultraviolet light.