As far as we know, in the earliest days after the Big Bang, light elements like helium appeared leaving the heavier elements to form later inside stars due to strong nuclear reactions.

 

I wonder if there are even heavier elements out there formed in supernova explosions that did not end up on earth. How likely/unlikely is that?

All the elements heavier than those we have seen on Earth are very unstable (which is why we don't see them).

All the elements heavier than those we have seen on Earth are very unstable (which is why we don't see them).

 

So you are saying that all the stable heavy elements that exist have been discovered and are here on Earth and it's unlikely to find new ones outside Earth?

 

So you are saying that all the stable heavy elements that exist have been discovered and are here on Earth and it's unlikely to find new ones outside Earth?

Yes. There is some potential for heavier elements which are more stable but we're still talking about half lives of minutes.

 

You might find this interesting (sorry about mobile link):

 

https://en.m.wikipedia.org/wiki/Island_of_stability

 

So you are saying that all the stable heavy elements that exist have been discovered and are here on Earth and it's unlikely to find new ones outside Earth?

 

If you will look at Wikipedia "Isotopes of [element name]" pages

f.e.

https://en.wikipedia.org/wiki/Isotopes_of_holmium

https://en.wikipedia.org/wiki/Isotopes_of_gold

https://en.wikipedia.org/wiki/Isotopes_of_lead

You will see whether isotope is stable or unstable, mentioned decay modes, and what is measured half-life.

There is also note "observatory stable", which means that theoretical models are predicting isotope is unstable, but scientists never observed it in reality.