Can planets exist forever or do they have a lifespan?

Life may or not exist elsewhere- 'but not, Jim, life as we know it!'

My belief is that we are a unique and beautiful planet with such a variety of life that I'm no longer interested in what might or might not be on other planets...
we need to appreciate the one that we've got instead of pondering on what is trillions of light years away...

Does anyone believe that life on other planets can exist randomly if left untouched?

Let me know as my grandson is very interested and i’m new to this phone!

As I understand it, the Universe is in a constant state of change. Whole galaxies are born and die in a mere twinkling of cosmic time.

So, no. I wouldn't expect any planet to exist forever in its current form, but to ultimately break down (or be destroyed by some event) and become part of another entity within the Universe.
As for Jupiter in the next 10-100 years? It will probably be quite similar to how it has been for however many billions of years it has existed in its current form.

😁

Well, that was resolved very speedily.

Don't worry.

In about five billion years time, the Sun will become a red giant and swallow us up before it starts to affect Jupiter.