ARSIA MONS FIELD NOTE OBSERVATION + MODEL

A cloud longer
than many countries.

Follow one observed morning near Arsia Mons, then compare what Mars Express saw with what a regional model suggests.

Study published · publication timezone unspecified
Featured Mars Express image recorded · orbit 18627

Mars Express view of a long white morning cloud stretching westward from the Arsia Mons volcano.
Mars Express orbit 18627 · September 21, 2018
ESA/DLR/FU Berlin · processing and acknowledgement J. Cowart · ESA image record ↗

01 / WATCH ONE MORNING

Observed cloud. Modelled mechanism.

  1. OBSERVED

    Morning recurrence

    Mars Express has observed the water-ice cloud during Martian southern spring and summer mornings.

  2. MODEL

    Air rises

    A regional model sends air upward over the roughly 20-kilometre-high Arsia Mons volcano.

  3. MODEL

    Rapid cooling

    In the simulation, a gravity wave lifts air parcels several kilometres and cools them about 30°C in 10 minutes.

  4. MODEL

    Ice nucleates

    The model reproduced a cloud when water vapour froze directly without dust particles acting as seeds.

  5. OBSERVED

    Long morning plume

    The recurring cloud can extend up to about 1,800 kilometres downwind before fading later in the morning.

The labels matter: Mars Express observations establish the cloud’s appearance and recurrence; the model proposes a physical explanation. CaptureMars does not turn the model into a measured wind field or a live forecast.

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02 / COMPARE THE EVIDENCE

A useful model that does not match everything.

Mars Express observation showing the Arsia Mons elongated cloud against the curved Martian horizon.
Observed. A real Mars Express image from September 21, 2018.
Split-screen ESA animation comparing an observed Arsia Mons cloud above with a regional model simulation below.
Observed + simulated. The upper view is observation; the lower view is the model. Reduced-motion devices receive a still frame.

ESA says the simulation’s timing, duration and cloud length do not exactly match the observations. Those differences are not a failure hidden by the visualization; they show where the explanation still needs work.

Study
Hernández-Bernal and colleagues, published online in Nature Geoscience
Evidence
Mars Express VMC, HRSC and OMEGA observations plus a regional atmospheric model
Globe anchor
Arsia Mons summit region. The marker uses the centre coordinate published with a NASA THEMIS summit-caldera image; it is not an exact cloud-origin point or mapped cloud boundary.
Not established
Current cloud presence, live wind direction or intensity, current weather, liquid water, life, habitability, safety or human zoning

Read ESA’s October 7 report ↗ · Open the peer-reviewed study record ↗ · Check the NASA summit-region locator ↗

If the images or animation cannot load, the dated sequence, evidence labels, limitations and primary-source links remain available as text.

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