Curiosity Confirms Origins of Martian Meteorites

littlesparkvt writes "Earth's most eminent emissary to Mars has just proven that those rare Martian visitors that sometimes drop in on Earth — a.k.a. Martian meteorites — really are from the Red Planet. A key new measurement of Mars' atmosphere by NASA's Curiosity rover provides the most definitive evidence yet of the origins of Mars meteorites while at the same time providing a way to rule out Martian origins of other meteorites."

Comments

The Key Word is "Confirms"

[mbone]

Curiosity is just confirming the results of the Viking entry science neutral atmospheric composition experiment (different from the mass spectrometer operated on the surface). It's very nice to have this nailed down, but I don't think it changes anything.

Re:The Key Word is "Confirms"

[Anonymous Coward]

indeed. I am still quietly waiting for when we find some life - perhaps even just proteins or evidence of life. It has been said many times over there years that aliens coming to Earth would change human society. I still hold hope that alien life on another planet would have the same effect!!!

Re:The Key Word is "Confirms"

[icebike]

So a sample of gasses violently encapsulated in molten rock after a impact of a rather large body upon a planet with enough force to eject significant amounts of rock has the exact same components as the atmosphere it was blasted through?

That's amazing. More amazing that a random rock from Mars landing on earth.

Re:The Key Word is "Confirms"

[Anonymous Coward]

Oh no it has not the exact same composition. But certain elemental and isotopic ratios are characteristic enough. Look at this abstract for example http://www.sciencedirect.com/science/article/pii/0012821X84901833

Re:The Key Word is "Confirms"

[beelsebob]

Well no... The thing about aliens visiting us is that it implies not only intelligence, but knowledge beyond ours. That's got major implications. Some random proteins a few billion miles away... not so interesting.

Re:The Key Word is "Confirms"

[Anonymous Coward]

Not that amazing when you're dealing with *isotopes* of a noble gas. There's not much opportunity for isotopic fractionation in an impact event and the subsequent rapid freezing of the melt to form glass. I'm sure the elemental composition of the gases has been skewed during the impact event, but the isotopic ratios of the argon? Not likely.

Re:The Key Word is "Confirms"

[Anonymous Coward]

Well, yeah, but "confirms to a much higher precision" is still worth a lot scientifically. As the article explains, previous estimates from Viking had the ratio of 36Ar to 38Ar at between 4 and 7. That's a pretty wide range. The new measurements place the current atmosphere ratio at 4.2+-0.1 (you have to look at the abstract in Geophysical Research Letters to get the uncertainty). An improvement by an order of magnitude or so is pretty nice, and it allows better estimates of the amount of atmospheric loss compared to the previous numbers from Viking.

Re:The Key Word is "Confirms"

[NoKaOi]

Well no... The thing about aliens visiting us is that it implies not only intelligence, but knowledge beyond ours. That's got major implications. Some random proteins a few billion miles away... not so interesting.

Not as interesting as aliens visiting us, but still having potential major implications just the same. Why? If there is evidence strong enough for the medial to call "proof" of life on another planet, it'll "prove" to the uneducated masses that there's a lot more interesting stuff out there than we know about, and that there really could be intelligent life elsewhere, so it's worth putting more resources into scientific research and maybe even education. Then again I'm probably being optimistic, and nobody would really care about finding life on other planets until we have licensing agreements for their reality shows.

Re:The Key Word is "Confirms"

[VortexCortex]

Well no... The thing about aliens visiting us is that it implies not only intelligence, but knowledge beyond ours. That's got major implications.

It's raining rocks again... Damn alien microbes, THEY KNOW this shit pisses me off. Insurance rates will go through the roof by the hole they just made. Bastards are too small to see or I'd wring their little necks. Clever, very clever... Stingy too! Practically gotta dissect 'em in a lab to get anything out of 'em -- Won't even share any of their advanced space traveling technology with us. Enjoy your petri dish acid bath, suckers! Stuck up, know-it-alls... Serves 'em right.

Re:The Key Word is "Confirms"

[nospam007]

"Curiosity is just confirming ..."

Curiosity has led to all the discoveries in the last couple of thousand years.
Just the cat got killed by it.

Re:The Key Word is "Confirms"

[Anonymous Coward]

Seriously, what gain would there be in proving that 'non-intelligent' life exists? How does it benefit us? Just proving does nothing unless we can go there and bring some of it back with either manned or unmanned craft. Even then, what kind of things would benefit us? Cures for diseases? That would just make things worse in the long run unless we have the ability to spread out and colonize space.

Unfortunate accident

[Laxori666]

Unfortunately, in the process of confirming the origin of martian meteorites, the rover ran over a martian cat.

Yep. One Mars

[garyoa1]

While scientists state that there has to be a countless number of earth like planets out there... there can only be ONE Mars like planet. Dam these guys are good!

Re:Yep. One Mars

[lxs]

Let's see on the one hand we have a confirmed Mars like planet nearby, at least orbiting the same star, on the other hand there may be faint evidence of Mars like planets so far away that we need huge resources to barely deduce a trace of their existence with no plausible mechanism of transporting that material to Earth. I'd say the chances are above 50/50 that Mars is the culprit.

Re:Yep. One Mars

[Sockatume]

The chances of anything coming from Mars are a million to one*, but the chances of anything coming from another solar system are mind-crushingly miniscule.

*see Wayne et al

Re:Yep. One Mars

[Anonymous Coward]

The chances of anything coming from Mars are a million to one*

I get the reference (one of my favorites), but given that the number of recovered meteorites is something over 30,000 and at least 60 (or more?) of them are of Martian origin, I'd say the chances are about 2000 times better than that. ;-)

With a heading like that

[OhANameWhatName]

Curiosity Confirms Origins of Martian Meteorites

I'm not surprised nobody is paying attention to the post

Re:With a heading like that

[VortexCortex]

Oh, only us usual suspects stick around and create comments when writers' alliterative affinities yield yet another absolutely heinous headline.

No no no

[Anonymous Coward]

You don't confirm things in science. More like, "Curiosity finding support the notion that.."

Re:No no no

[Sockatume]

Of course we "confirm" things in science, we just don't use the word to mean that something is unambiguously stated to be true. When we use that word (and it's used ubiquitously) we mean that we're providing new evidence for a previously-accepted hypothesis.

Everybody sing!

[Tablizer]

Argon, *clap* *clap*, Argoff

Was mars once like earth?

[issicus]

I can't believe there hasn't been I sci-fi movie about this already. Is some way that mars could have once been like earth, but something happened. I'm still working on my degree in BS , so the only explanation I could come up with is Martians somehow used heat from the core of Mars to power their civilization, but in their bureaucratic greed cooled the core so much that it no longer created a magnetic field around Mars. Death fallowed shortly after....

Re:Was mars once like earth?

[Sockatume]

It's a popular idea in SF. The "Earth-like Mars" part, at least, not sure about the bureaucracy part. I'm playing through a lovely iPhone game called Waking Mars right now which has its own take.

Who shot first?

[Anonymous Coward]

Was it Mars or Earth?

No such things as Xenomorphic Climate Change

[abies]

There was no Xenomorphic Climate Change on Mars. It is all natural process and if you observe last 15 years of data, you can see sharp increase in Mars average temperature, which clearly shows that previous billion years cool period is just cyclical and natural and very soon we will again have green Mars. Nobody has shown conclusive proof that PB and Llehs geometermal extractors have any influence on Martian atmosphere. Let's remember that climatology is not a strict science and you cannot generalize observations from periods as short as billion years. CO2 measurements from Martian rock layers clearly show that Mars was having climate issues 3 billion years ago and it turned out to be all good after all.

Re:No such things as Xenomorphic Climate Change

[issicus]

to bad the martians didn't survive to see the next green age...

It's all in the name

[watermark]

Martian meteorites come from mars

Re:XP user use Chrome?

[Anonymous Coward]

I do
(Ise anything besides IE that is)
Well lets put it this way I don't use IE
I mainly use Firefox
and Seamonkey
And ComodoDragon
but I don't use IE

No they didn't

[hAckz0r]

No, What they confirmed is that the meteorites found on Mars surface are the same as the ones that fell to earth. Why oh why would one think that different rocks will only fall on certain planets? And what makes them think for a minute that argon does not exist elsewhere in the Universe? Where do they think Mars got its Argon from?

.
Argon is a heavy gas, and yes it is more likely to settle on a planet that has lost atmosphere, but Mars is not the only place that it can happen, its just that they want to believe they have rocks from Mars so they will tailor the data to make their facts fit even when other possibilities exist.

When supernovae occur, different elements are going to be created at different compression levels within the expanding ring around the epicentre. Different regions blown off from it will be naturally higher in certain elements, and those elements will then be distributed in different density patterns around that region. Some formations will be naturally higher in Argon than others, and therefore certain rocks/asteroids formed from those materials will have different distributions of those elements. All these rocks are flying around up there haphazardly with nothing but angular velocity and gravitation to direct their decent to different planetary systems. To think that the same rocks that landed to 'form' nearby Mars could not ever wind up on Earth is complete nonsense. Until volcanic and tectonic forces assimilate that fallen material there is no telling them apart. Shergottites, Nakhlites, and Chassigny? Show me an igneous rock with these same Argon characteristics and then I might listen to these claims.

Re:No they didn't

[Anonymous Coward]

What do supernovae and any kind of isotopic differentiation in them have to do with anything? The stuff that made up the solar system spun around and was pretty thoroughly isotopically mixed. Any isotopic differentiation would be long gone unless you're able to find intact pieces of material from the time before the protoplanetary disk that formed out solar system began. Otherwise it may as well have gone through a blender. It's pretty much a single batch, isotopically-speaking, and changes in Ar isotopic ratios in atmospheres are largely a result of ongoing radiogenic contributions (relevant for other Ar isotopes but not relevant for 38Ar and 36Ar) and other processes such as atmospheric loss.

Yes, the Earth and Mars did start off with much the same Ar isotopic ratios from the meteoritic material that fell onto them. But what was in the atmosphere diverged from there due to dramatically different processes, largely due to differences in gravity.

As far as I know, Ar does not significantly isotopically fractionate within the atmosphere. The atmosphere is too well-stirred. The fractionation occurs high in the atmosphere at the interface with space, where the relative velocities of heavier versus lighter Ar isotopes at a given temperature change the average escape velocities. Heavier Ar does not "settle" onto a planet, it gets left behind as the lighter isotopes escape more easily. It also isn't about the abundance of Ar in total in the atmosphere. Just the isotopic ratios regardless of the concentration that is there.

This also isn't about rocks falling to the respective planets early in their history, it is about rocks FORMED on those planets (i.e. melted and then crystallized or frozen into glass) and trapping some atmosphere at the time. The SNC meteorites aren't preserving Ar isotopic ratios from the time of accretion of the whole planet. The rocks are younger than that, as was their ejection from Mars. They are chemically differentiated basalts and related rocks that imply they were thoroughly melted and then solidified ON A PLANET before the impact event that ejected them -- i.e. what you describe as "assimilate that fallen material". Yes, been there, done that. Then they were shock-melted during the impact along fractures, and the resulting glass trapped bits of the atmosphere while the majority of the rock remained its very planet-like composition, as opposed to the majority of meteorites that show relatively little chemical differentiation typical of smaller bodies.

I don't think you really understand how the process is thought to have worked.

Re:No they didn't

[Anonymous Coward]

After years of failing to prove his intellectual superiority, GP thought he could reverse the tide today. He applied his finest reasoning to his deepest knowledge of physics in a bitter attempt to shame the latest crop of researchers by destroying their conclusions in a public forum. It didn't work. Next time maybe.

Really?

[CCarrot]

Curiosity Confirms Origins of Martian Meteorites

Funny, I thought it was only good for killing cats...badum-ching!

Thank you, thank you, remember to tip your waiters, I'm here all week! :P