Cassini Detects Complex Organics in Enceladus Plumes

A team led by Nozair Khawaja reanalyzed archived Cassini data and report detection of complex organic molecules in fresh ice grains ejected from Enceladus’ plumes, with results published in Nature Astronomy. The grains were sampled by Cassini’s Cosmic Dust Analyzer during a 2008 plume flythrough at roughly 18 km/s and are estimated to have been only minutes old, reducing space-weathering and preserving clearer chemical signatures. Mass spectrometry reveals a richer inventory of organics, including indications of nitrogen- and oxygen-bearing compounds, adding to earlier detections of carbon, hydrogen, nitrogen, oxygen and phosphorus in Enceladus’ ocean. The authors say the molecular complexity points to active chemical pathways that could produce biologically relevant compounds, substantially increasing the moon’s habitability potential while stopping short of evidence for life. The finding bolsters scientific interest in follow-up exploration and strengthens calls for dedicated orbiters and landers to probe Enceladus’ subsurface ocean directly.