Mars’ wet streaks might not be wet

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The uncertainty of science: An analysis of five years of data from Mars Odyssey suggests that the dark streaks flowing down Martian slopes might contain very little and possibly no water at all.

This year, planetary scientists Christopher Edwards and Sylvain Piqueux took a closer look at the feature using a thermal imaging instrument on board Mars Odyssey, another orbiter. They found no temperature differences between the dark RSL streaks and surrounding terrain — which suggests that the streaks aren’t really patches of wet sand streaming down a slope. At best, they say, the RSLs could contain no more than 3 percent liquid water — making them more like mildly damp, slightly salty dirt. And that’s an optimistic interpretation, Edwards said; it’s possible the RSLs contain no water at all. “Why this process is happening in this area, or what is causing this darkening, I don’t think is exactly obvious at this point,” he continued. “But to say it’s flowing liquid water, I don’t think it’s the whole story. It’s not necessarily even the right story.”

This data once again illustrates why we must be very careful with our conclusions when looking at features on an alien world that seem to resemble things we are familiar with here on Earth. Just because they might look alike is not evidence that they are the same. Mars has a very different gravitational field (one-third of Earth’s) and a significantly different make-up. We might be witnessing processes we’ve never seen before that produce features that mimic Earthlike forms.


  • All this goes to the fact alien worlds are hard to study from millions of miles away. But it also shows NASA all the quick to go with a big publicity stunt. The whole water on Mars event screamed bad idea but NASA did it anyways. It very in line with the Obama way of thinking, win the new cycle people generally remember the first story they hear not the correction 3 days later or months later in this case.

    This whole publicity before science is one of the many reason NASA is where it is today a failing government agency that seems to have its best years behind it.

  • Localfluff

    If even the Recurring Slope Lineae are dry and dead, maybe there will be a last propaganda rush to Europa, the icy moons? Lots of water to follow there, to discover the playful dolphins which are of course swimming inside of it. Bad news for astrobiologists. It’s much safer for the career to study stuff that really exist. Nah, I don’t want to be evil on them. They are doing a great job trying to find out what might be habitable. But they are much more biology than astro.

    The only real overarching theory in biology is evolution, and that is kind of a truism. Lots of great theories about genetics, connectomics and even stranger stuff. But no big theory like the lambda-CDM model of the universe, its structure and origin.

    But it’s good news for human space flight! Now the “planetary protection” mafia lost their argument against landing humans on Mars! And sample return and whatever other science progress the haters want to stop. Mars is dead, but we will bring it alive. We must do it now while we can.

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