Every so often we get a reminder that all scientific conclusions are provisional.
The canyon-like scars which line Mars’ crust are seen by many as evidence for liquid water. But a study now suggests that a different kind of fluid – one much less hospitable to life – may actually have carved these features.
The article is careful to point out that this possibility doesn’t necessarily eliminate water from Mars’s past, or erase the potential of life. But it does seem like the features that looked like water eroded formations were a source of comfort for those hoping to find life on Mars, or evidence of past life. That evidence might still be there, but if the results of this study hold up, that hope seems more forlorn.