I really find the 'habitable planets' discussion very interesting - along with the Fermi Paradox.Just reading the life on venus thread
space frazzles my Brain and so much my pea brain cant grasp.
like that there are more planets in the universe than grains of sand On earth
and that space is always expanding! Well whats it expanding into?
And that some stars we see arent actually there anymore
Let's say we are incredibly, ridiculously rare and that the chance of Earth becoming what it is was around 0.00001%.
In the Milky Way (so just our galaxy, remember there are trillions of galaxies in the universe, but we will just focus on ours) there are Sextillion (1,000,000,000,000,000,000,000,000,000,000,000,000) 'earth-like' planets. If we apply our 0.00001%, there are still trillions and trillions of planets that should harbour life as advanced as Earth. Also, chances are the chance of life developing in some form is higher than that percentage (as we can see a bit of evidence for life in Venus and potentially Mars).
Now, remember that is literally 'planets'. We already know there is evidence of microbial life on comets. We know that various moons (Titan for example) could potentially harbour life.
Mathematically it's inevitable complex life exists/existed.
So there must be a 'great filter' that either prevents life getting to where we are (which means we've passed the great filter - very good, but lonely news) OR there is an earth ending filter ahead of us, that stops us from being complex enough to venture to other inhabited places.