According to Viking Data Suggests Life? by Universe Today republished at NASA's Astrobiology Magazine:
"Researchers from universities in Los Angeles, California, Tempe, Arizona and Siena, Italy have published a paper in the International Journal of Aeronautical and Space Sciences (IJASS) citing the results of their work with data obtained by NASA's Viking mission."
ANd "Is it Snowing Microbes on Enceladus?" online at Science.nasa.gov:
"There's a tiny moon orbiting beyond Saturn's rings that's full of promise, and maybe -- just maybe -- microbes. In a series of tantalizingly close flybys to the moon, named "Enceladus," NASA's Cassini spacecraft has revealed watery jets erupting from what may be a vast underground sea. These jets, which spew through cracks in the moon's icy shell, could lead back to a habitable zone that is uniquely accessible in all the solar system."
I am a biologist. Back in the day I ran many NASA peer review panels for exobiology research and helped plan NASA's initial astrobiology program. I run astrobiology.com and would absolutely love this story to be true i.e. microbes raining on Enceladus but ... its not true - at least no one has proved it. Dr. Porco's guesses are imaginative and inspired and are not without some strong supporting data but they are just guesses - and Cassini does not have any way to prove that there is anything alive in these plumes. So yes, "let's go back".
As for Gil Levin's Viking research, a quick check will show that this journal is mostly run by Korean scientists and seems to have little stated expertise when it comes to astrobiology or exobiology (at least none that I can determine). Levin regularly publishes re-written papers that all point back to a claim that he has been making for decades i.e. that his experiment on the Viking landers found life on Mars - or at least some solid evidence of its possible existence. Who knows, Mars is a much different world than we thought it was back in the 1970s. Again, I'd be ecstatic if his claims turn out to be true but no one really agrees with him.
Why am I being such a wet blanket? At a time when climate change deniers are criticizing NASA for the way it selects and interprets its science, one would think that the agency would at least exercise a little more caution in putting things on its official websites that either jump to conclusions, or prompt the reader to do so. Indeed, I cannot find a simple policy that the agency adheres to in this regard. Not to have a clear policy that is enforced simply makes it harder for NASA to refute some of the attacks that others throw against it.
After last year's fiasco with the 'life in meteorites' paper claims by NASA MSFC's Richard Hoover, you'd think SMD and the Astrobiology Institute would be paying a little closer attention to this matter. I have sent comments to NASA's astrobiology folks but no one bothers to respond.