Nobody has ever given an intelligent answer to what is intelligent life, but to simplify, yes, life itself could develop on a rogue planet. It might be a microbe or something greater, but we know here on Earth, deep below in the oceans where no sunlight reaches, there are forms of life that live and thrive due to the heat of volcanic tubes erupting.
Life needs energy. It doesn’t always have to get that energy from the sun. There must, however, at least be some heat.
The answer is yes.
It’s already proven. The nearest possible candidate for life other than microbes is 40 light years away. Traveling at the fastest speed ever achieved it would take over 3000 years to reach that distance.
So that proves we are not aliens, we’ve never been visited by aliens, and we will never be able to visit other stars to know if there are aliens.
Well, statistically and evidentially, yes.
Statistically, there are thousands and billions of galaxies, each consisting of billions of stars, and each star generally has at least one orbiting planet, it is highly likely some form of extraterrestrial life exists out there.
Evidentially, we have seen plumes of gas coming from moons around Saturn, suggesting a warm liquid ocean underneath a sheet of ice, a good place to look.
However, and I don’t mean to burst your bubble, but to date no evidence of life anywhere else but here on Earth has ever been found. We have not even found a fossil of a microbe on a meteorite. Nada.
We believe life is out there, but we have no proof to date that life has developed anywhere in the universe other than Earth.
In my opinion, hopefully neither place because there is no valuable reason for humans other than our robots to establish a presence in either place. Robots are expendable and you don’t have to bring them back. They can transmit what they find. Both are dead planets. Both have no reason to settle there.
Some of my readers embrace my pessimism. Some hate it!
Finding life on other planets is the Holy Grail of science. The final punch in the age-old fight between scientists and creationists. It runs deep.
It would finally prove life can exist elsewhere. To date no proof exists.
There are candidates right here in our own solar system with some moons in orbit around Saturn and Jupiter. They are going to spend a lot of money to look. They had hope for Mars. That hope faded quickly when we realized Mars is dead.
My gut feeling is on the side of pessimism, though.