I read a news article about a probe headed out to Jupiter. At the end of the article, it mentions a fear of "contaminating" the moons if it does not end it's life on Jupiter itself:
Juno's electronic heart is protected in a vault of titanium, but it too will fall to the harsh Jovian radiation environment after about a year. Juno's last move will be to dive into the planet's atmosphere to avoid any chance of contaminating Jupiter's potentially life-bearing moons.
Is it really possible that life - at least as we have so far observed it - to exist in this solar system so far away from the sun? Could a life-supporting atmosphere provide ample protection from solar radiation as well as temperature?