Editor’s note: In these last two weeks of 2021, we’ll be looking at a few selections that we haven’t yet discussed on AAS Nova from among the most-downloaded papers published in AAS journals this year. The usual posting schedule will resume in January.
The Science Case for a Return to Enceladus
Published July 2021
Main takeaway:
A team led by Morgan Cable (Jet Propulsion Laboratory) proposes that Saturn’s icy moon Enceladus should be the target of a future spacecraft mission. The moon’s water plumes are unique in the solar system and provide unparalleled access to the salty, organic-rich ocean beneath the crust — an environment brimming with astrobiological promise.
Why it’s interesting:

A backlit view of Enceladus’s south polar plumes. [NASA/JPL-Caltech/Space Science Institute]
What kind of mission would be best:
Given the existing evidence for an organic-rich water ocean, Cable and coauthors say we already know that Enceladus is habitable, so the logical next step is to send a dedicated life-finding mission. It may be possible to probe Enceladus’s oceans in a minimally invasive way by sending a spacecraft to fly repeatedly through its plumes and analyze the droplets. A lander or rover could undertake more sensitive experiments, searching for life-signaling organic molecules like amino acids and lipids. A mission to Enceladus would require roughly 11 years to travel from Earth to its home in orbit around the moon — so what are we waiting for?
Citation
Morgan L. Cable et al 2021 Planet. Sci. J. 2 132. doi:10.3847/PSJ/abfb7a