Overview
- The Nature Geoscience paper published Oct. 7 reports that new Mars atmospheric models that include homogeneous nucleation reproduce key features of the Arsia Mons Elongated Cloud (AMEC).
- Researchers say strong gravity waves triggered as winds flow over Arsia Mons lift moist air several kilometres in minutes, cooling it by about 30°C in ~10 minutes and producing the extreme supersaturation needed for vapor to freeze directly into ice.
- Homogeneous nucleation requires humidity levels far above ordinary Earth conditions—authors quote relative‑humidity spikes on the order of 100,000 times typical terrestrial values—which explains why AMEC forms without dust or other ice nuclei.
- The result rests on repeated morning observations from ESA’s Mars Express (VMC, HRSC, OMEGA) and on simulations that for the first time generate AMEC’s long tail, but the team acknowledges persistent mismatches with some observed details.
- Confirming the hypothesis will require new targeted morning measurements that are hard to obtain, a step that would reshape cloud physics for Mars, inform study of other planets and exoplanet atmospheres, and guide future mission planning.