Weighing mainstream and alternative accounts…
Two lenses on the same evidence. Source weight and the primary source ratio show what each rests on.
Deeper threads worth pulling on next.
Investigated
No Mars probe is shown here directly measuring individual nucleation events. ExoMars TGO/NOMAD remotely measured cloud abundances, particle sizes, temperatures, and dust or ice distributions; researchers used those observations with theory to infer likely nucleation mechanisms, while the direct nucleation measurements came from Earth-based laboratory experiments.
Two lenses on the same evidence. Source weight and the primary source ratio show what each rests on.
Lens adapted to this topic: Remote signatures may reveal the mechanism indirectly
A narrower but important qualification is that “directly” can mean directly observing signatures diagnostic of a mechanism, rather than measuring molecular cluster formation. TGO/NOMAD data have been interpreted as evidence for dust- or water-ice-assisted nucleation in some settings, while unusual cloud morphology has been used to argue for homogeneous nucleation. These are observational inferences, not direct nucleation measurements.
Deeper threads worth pulling on next.