Plume Ice Grains Concentrate Biosignatures

Laboratory experiments and modelling indicate that water droplets ejected in Enceladus’ plumes freeze slowly and undergo physical separation that concentrates salts, organics and potential microbial material into individual ice grains. Those grains, when they collide with surface fissures, could preserve discrete, concentrated biosignatures that spacecraft could detect more easily than a dilute plume sample. — If true, this changes mission design and detection strategy (sampling many individual ice grains rather than bulk plume analyses), with downstream effects on what missions are funded, what instruments are prioritized, and how planetary protection rules are set.