Spectral Evidence for Hydrated Salts in Seasonal Brine Flows on Mars [pdf] | Hacker News Reader

Spectral Evidence for Hydrated Salts in Seasonal Brine Flows on Mars [pdf]

meetingorganizer.copernicus.org

33 pointsmychaelangelo11 comments

It was already known that liquid water can exist on about half of Mars, though in a very narrow temperature range (around 0C).

The green and blue bits have the adequate pressures for liquid water to exist:

https://upload.wikimedia.org/wikipedia/commons/2/2c/Mars_top...

Very narrow phase-space in which liquid water can exist, the yellow rectangle is conditions on Mars:

https://i.imgur.com/BeDg1KM.gif

This isn't the big news scheduled for tomorrow, is it?

My layperson's opinion is that it is.

The paper reports data indicative of transient liquid salt* water flowing on current day Mars (as in, in the past year), answering the "mystery" of the apparent daily sand flows in pictures previously seen.

That's sort of huge, because wow at confirming liquid water there pretty much right now, but it's also a bit of a hollow thing to reveal, as it's just solid confirmation of something strongly suspected for many months.

* Exactly _what_ salt is not super clear, I think? Mg-perchlorate and Mg-çhlorate are mentioned, but the exact mineralogy isn't able to be stated from the current results.

Yeah, it's cool, but it's not really a "major announcement."

Still, science marches forward.

I think having a potential recurring source of liquid surface water is a big deal for both human and automated missions. It's rocket fuel and the stuff of life for us squishy things and not having to take so much would dramatically lower the launch weight and make long term habitations possible.

From my perspective this is pretty major. It was not very long ago that we had no proof of liquid water on any other rock in our solar system.

We know that Enceladus and Europe have liquid water.

True, but to be fair the parent said "not long ago" and this is quite the case, it was only ten years ago that we first observed vapour plumes on Enceladus, and I think Europa's subsurface ocean hypothesis started to gain traction around the same time. We live in exciting times.

The proof for both is from this millenium (from Galileo and Cassini probes). To me it's still fairly recent. While I find the principle of induction does trivialize lot of mathematical calculations I cannot apply the same principle of non-wonderment to discoveries made in the material world.

For those of us who don't follow these things closely while the researchers involved are forming and confirming their theories, it's pretty big news.

But yes, science marches forward. Perhaps it'd march a bit faster with more funding, but so it goes.

Just to follow up with further evidence that NASA's announcement[1] is about this research: in attendance at the conference today will be Lujendra Ojha of the Georgia Institute of Technology, the principal author of the linked paper, and Alfred McEwen, the principal investigator for the High Resolution Imaging Science Experiment (HiRISE), also with authorship on this paper (which uses HiRISE extensively).

1. https://www.nasa.gov/press-release/nasa-to-announce-mars-mys...

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