There Were Mega-Tsunamis On Mars (popularmechanics.com)

An anonymous reader quotes a report from Popular Mechanics: Today, a team of scientists has announced the first discovery of extraterrestrial tsunamis. A team of astronomers and geologists led by J. Alexis Rodriguez at the Planetary Science Institute in Tucson, Arizona has uncovered evidence of massive tsunamis on Mars billions of years ago. As Rodriguez reports, two separate mega-tsunamis tore across the red planet around 3.4 billion years ago, a time when Mars was a mere 1.1 billion years old and nearby Earth was just cradling its first microbial lifeforms. The two tsunamis created 150-foot-high shore-break waves on average, and some absolutely monster waves up to 400 feet tall. Rodriguez and his colleagues outline their tsunami findings today in the journal Scientific Reports. From the report: "Rodriquez and his colleagues stumbled across evidence of these tsunamis while scouring over images of Mars' relatively flat northern planes. Two regions called Chryse Planitia and Arabia Terra. Using detailed infrared maps rendered by the thermal camera on the 15-year-old Mars Odyssey orbiter, the scientists identified the high water marks of the tsunamis -- features that look a lot like ancient ocean coastlines." Within the last year alone, scientists have spotted the signs of flowing water on Mars, recently discovering how water flows on the red planet. NASA has detected atomic oxygen in the atmosphere of the planet, too.

Comments

Makes sense

[krkhan]

a time when Mars was a mere 1.1 billion years old and nearby Earth was just cradling its first microbial lifeforms.

And Keanu Reeves was the upcoming A-lister in Point Break.

Why are Mars oceans blue and not green?

[jfdavis668]

Every simulated image I see of oceans on Mars shows them as blue. Earth's oceans only turned blue after life poisoned them with free oxygen. Before that they were green from dissolved iron.

Re:Why are Mars oceans blue and not green?

[Tablizer]

Actually the blue seems to be mostly the reflection of the Earth's sky. The actual ocean is kind of a dark muddy green on average. But if you look at the water from an angle, it's blue, like the sky, regardless of the water color.

I'm not sure the color of Mars' sky back then. Now the color is mostly driven by dust particles because there's so little actual air, but Mars had a thicker atmosphere in the past, before it lost its magnetic field.

Re:Yup

[mrsquid0]

Bolides are moving fast enough that they do not even notice the atmosphere. The impact velocity is going to depend on the orbital dynamics of the planet and the rock.

Re:Trading seasons

[Rei]

There's this real effort to portray it as more Earth-like, but I'm not buying it.

Let's just look first at that big deal made about the findings of atomic oxygen. Atomic oxygen occurs almost everywhere in the solar system. Wherever solar wind hits water vapour or ice, you get atomic oxygen. It's a complete nothing story.

The whole thing about "signs of flowing water"? It's beyond an exaggeration to call that "flowing water". A better description would be "transient flows of organics-destroying rocket propellant". Those perchlorate flows are what you would use to destroy LAWKI, not create it.

As for "boiling water possibly shaping Mars" - not any time recently. Our global data on Mars suggests that, at least within a couple hundred meters of the surface, there is no liquid groundwater on Mars.

I've seen other things both about the past and present making wild claims as well. For example, some people making a big deal about how "Mars had a past oxygenated atmosphere and life!" because they found a manganese "rock varnish", and such rock varnishes need a strong oxidizer like oxygen. Never mind that if you actually read the paper they point out that Mars's near-ubiquitous perchlorates are also powerful enough oxidizers. They didn't find them at that exact location at that exact time, but seriously, as if that's supposed to mean anything? They talked about how the "varnish" was just a thin coating and made a big deal of it. Except they found it in a known geothermal area. Geothermal springs depositing thin coatings on rocks is what they do.

Another one: the "methane on Mars". Class this one under the "atomic oxygen" category. They've found tiny amounts of methane. You know, the gas released by volcanism, on a planet that has the largest volcano in the solar system. An amount that would be associated with only a small fraction as much volcanic activity as Earth. An amount that could be readily trapped in permafrosts and seasonally escape. No evidence at all that it matches a life-related isotopic signature. Usually undetectable on the surface. Wow, color me impressed. ;)

All of these grasping at straws things come amidst a wealth of data that shows Mars to be a terrible place to look for life. No liquid water anywhere near the surface. Organics-destroying compounds ubiquitous in the environment. Meaning not only that they would have destroyed any LAWKI present, but that they're not finding anything organic to react with faster than the (slow) rate that they're created, and that no unusual exotic form of life is consuming them either. Minerals in forms rare or nonexistent on Earth in nature, even in ancient layers, suggesting that even then the environment was not Earthlike.

We've been obsessing over "life on Mars" for long enough. If we want to find life in our solar system, our best bets are subsurface oceans (Europa, Enceladus, Titan, etc). Or perhaps non-LAWKI on Titan's surface.