As far as I know, up until recently, scientists, in their search for life outside of our planet, have focused on searching for planets with the exact same characteristics as Earth. The main focus was finding a planet that lives inside the so-called Goldilocks zone, a planet that is in the right distance to sustain water. But their focus has now shifted. They now believe that liquid is a breeding ground of life. Any liquid, not just water. They even think perhaps life can be on a moon, not only on a planet. Take Europa or Titan for example. 

What’s really fascinating is that it opens up the possibilities of finding life exponentially. Here’s a great article speculating the possibility of life inhabiting Alpha Centauri B’s system. 

Fascinating.

Read more about it here: Super-Habitable World May Exist Near Earth

Photo credit: Wikipedia