Lets talk about life on Pluto…
Look at this picture I an gently stealing from spaceweather.com
The interpretation of the blue haze around Pluto is tholins, you can look up more here Miller Urey_experiment
, this could result in a rain of potential biologic gunk. I refer to this as potential biologic junk because it is pieces and bit, and certainly not critters falling from the sky. The nature of the surface of Pluto would be very hostile to life existing, something about ambient temperatures in the local of absolute zero.
However, Pluto is for the most part a slushball in space. To get things even better we have orbiting around a common center with its moon Charon. This is enough to induce something akin to plate tectonics, with plate tectonics, material on the surface could eventually be delivered towards the core where it would be protected from the radiation of the sun, and also possibly warmer and with enough fluid to allow it to interact.
This could allow a very basic form of life to evolve. The standards of what is life in this case are basic, replication, and usage of energy sources such as chemical reactions to sustain a cycle. The most similar life on Earth would be anaerobic bacteria around volcanic vents in the ocean, but the standards of what is life can be simplified greatly when you are looking for the base forms.
There will not likely be any little green men on Pluto, I would say the odds of Marvin the Martian popping up somewhere very close to zero. I would put the odds of finding something akin to extremely basic extremophile bacterial forms somewhere in the 50/50 range. I would personally say that when you are looking for life in the solar system the places to look would be Mars, Europa, and Pluto as first choices for exploration. They are the wettest, and although they may not have anything crawling around on the surface, once you get down into the bodies you may find they have all kinds of interesting things.
If you found life on Pluto, the rest of the Kuiper belt would be a far more interesting place for exploration. The odds of getting a lander on Pluto capable of actually doing this kind of exploration in my life time are very slim, but we could possibly, in my life time take a look at Mars and Europa. I am curious, I will always be curious, I want to know more.
Are we alone? I say no, absolutely not. Maybe if we just looked a little harder and more carefully we would discover just how teeming with life the universe actually is.