Overview
- The study published Wednesday models the Arsia Mons Elongated Cloud (AMEC), a daily dawn cloud that can stretch roughly 1,100–1,800 km and then vanish within hours.
- Researchers found their simulations matched the long thin tail of the AMEC only after adding homogeneous nucleation, a process where water vapour freezes into ice without dust or particles.
- The team links formation to powerful gravity waves driven by winds over the 20 km high Arsia Mons that lift air rapidly, cooling parcels by about 30°C in roughly 10 minutes and spiking relative humidity.
- Mars Express observations from its Visual Monitoring Camera, HRSC and OMEGA were central to the work, but the paper notes remaining mismatches between modelled and imaged details that require independent morning‑time measurements to resolve.
- If confirmed, the result expands the range of processes scientists must consider for Mars and other worlds, and points to a need for more dawn observations from orbiters to test how uncommon homogeneous nucleation is in planetary atmospheres.