Question: Is it true that the sun will blast a trillion years later and we all have to move to another planet because Earth is the 3rd closest to the sun?

Columbus Flight Directors answered on 4 Oct 2015:

Sergio:
Yes Zanita, that is true, the Sun will die sooner or later.
And with it the Earth will die. And with the Earth, also the human race would die, with all the good things we have done so far, all the memory of Shakespeare, of Leonardo, of Newton, all the art, the music, the science.
This, unless we’ve been good enough and found a way to colonize other planets. For that we have to prepare for it, we have to learn how to leave the Solar system.
This is why going to space today, even if it is only 400 km away, is doing something for the immortality of the human race.

Luckily as you said, we still have a lot of time before that happens, so we don’t have to worry too much for ourselves. But the challenge is big, so it’s good to start well in advance!

Simon:
Hi Zanita: One additional point from my side to make your mind boggle: The Sun is roughly middle aged being around 4 billions year old. It is expected to remain relatively stable for another 4 billion years before it will expand into a Red Giant and engulf the inner planets including Earth. 4 Billions years is a really long time. It took that long for all the life on Earth that you see around you to develop from single celled lifeforms. So the question I find most interesting is not will Humanity survive the end of the Sun or not, but what will we have evolved into by then?! Do you have any ideas?