https://www.cnet.com/news/saturn-moon-enceladus-offers-tantalizing-new-hint-its-habitable/

Beneath its frozen shell lies a subsurface ocean that has some source of warmth and some very interesting chemistry going on. Last year, scientists used data from the now deceased Cassini spacecraft to determine that the basic building blocks of life, including molecular hydrogen, are present in Enceladus' ocean. 

Now new research finds that much larger and more complex organic molecules can also be found there. This amounts to a big step forward in the search for alien life.