The Red Planet’s iconic rusty dust has a much wetter history than previously assumed, find scientists combining European Space Agency (ESA) and NASA spacecraft data with new laboratory experiments on replica Mars dust. The results suggest that Mars rusted early in the planet’s ancient past, when liquid water was more widespread.

However, new analysis of spacecraft observations in combination with novel laboratory techniques shows that Mars’s red colour is better matched by iron oxides containing water, known as ferrihydrite. Ferrihydrite typically forms quickly in the presence of cool water, and so must have formed when Mars still had water on its surface.

  • jol@discuss.tchncs.de
    10·
    3 months ago

    Did you read the article? We know it’s rust, but there are many forms of iron oxide that form in different conditions.

    Previous studies of the iron oxide component of the martian dust based on spacecraft observations alone did not find evidence of water contained within it. Researchers had therefore concluded that this particular type of iron oxide must be hematite, formed under dry surface conditions through reactions with the martian atmosphere over billions of years – after Mars’s early wet period.

    However, new analysis of spacecraft observations in combination with novel laboratory techniques shows that Mars’s red colour is better matched by iron oxides containing water, known as ferrihydrite.