I think of it like this, thinking about this with the drake equation.
there are 10 Billion stars in the observable galaxy.
Now look at it like this, our star is just one of them. Now in our solar system consists of 8 planets, 4 of which are rocky planets, a couple of dwarf planet candidates, over 200 moons (we are still finding more now)
We can categorically say currently, as of now, life exists on one of these bodies, earth.
There are however, hopefully soon (within 5 years) to be confirmed that life took hold at one point on Mars, possibly Venus, and current possibility of life in the seas of Europa and Enceladus, some debate is still occurring around Titan and also Ganymede.
This time 20 years ago we assumed the only energy source in the life requirement was the sun, we will soon confirm that if life exists in any liquid environment that heat can also be tidal forces, shifting tectonics, etc.
so lets say in the next 10 years we confirm current life outside of earth in a few places on those moons. Then we can deduce that over the life of our solar system, life has occurred in 5-6 of the 210 celestial bodies.
That would then say that life, at the microbial level is plentiful.
Considering that for every star there is at least one planet (drake equation)there are billions of possibilities.
The real question is how often does it reach intelligence?