From the University of Michigan
How Mars’ atmosphere got so thin: New insights from Curiosity
ANN ARBOR—New findings from NASA’s Curiosity rover provide clues to how Mars lost its original atmosphere, which scientists believe was much thicker than the one left today.
“The beauty of these measurements lies in the fact that these are the first really high-precision measurements of the composition of Mars’ atmosphere,” said Sushil Atreya, professor of atmospheric, oceanic and space sciences at the University of Michigan.
Atreya is co-author of two related papers published in the July 19 issue of Science, and co-investigator on Curiosity’s Sample Analysis at Mars (SAM) suite of instruments, considered the rover’s cornerstone lab.
SAM measured the abundances of different gases and isotopes in samples of Martian air, according to NASA. Isotopes are variations of the same chemical element that contain different numbers of neutrons, such as the most common carbon isotope, carbon-12, and a heavier stable isotope, carbon-13, which contains an additional neutron.
SAM analyzed the ratios of heavier to lighter isotopes of carbon and oxygen in the carbon dioxide that makes up most of Mars’ atmosphere today. Measurements showed that heavy isotopes of carbon and oxygen were more abundant in today’s thin atmosphere compared with the proportions in the raw material that formed the planet (which scientists can deduce from proportions in the sun and other parts of the solar system.) This provides not only supportive evidence for the loss of much of Mars’ original atmosphere, but also gives clues to how the loss occurred. It suggests that the planet’s atmosphere escaped from the top, rather than due to the lower atmosphere interacting with the ground, NASA’s web story states.
“The isotope data are unambiguous and robust, having been independently confirmed by the quadrupole mass spectrometer and the tunable laser spectrometer, two of the SAM suite instruments,” Atreya said. “These data are clear evidence of a substantially more massive atmosphere, hence a warmer, wetter Mars in the past than the cold, arid planet we find today.”
Curiosity landed inside Mars’ Gale Crater on Aug. 6, 2012, Universal Time.
For the full NASA story, see: http://www.nasa.gov/mission_pages/msl/news/msl20130718.html
duh? loss through interaction with the ground? whoever suggested that?
even Earth is losing atmo from the top, right now.
Is it our fault?
The telegraph also covered this topic with the article “Mars’ atmosphere destroyed by ‘catastrophic’ event four billion years ago” at: http://www.telegraph.co.uk/science/10189828/Mars-atmosphere-destroyed-by-catastrophic-event-four-billion-years-ago.html#comment-968396281
I left a “sarcastic” comment that is so patently idiotic that I’m thinking it won’t be taken seriously, but if it is taken seriously it’s meant to inspire a strong skeptical reaction. “Recommend” it to bring it to the top, This is the comment:
This is confirmation of the long established idea that small planets lose their atmosphere through
what you could call “fractioned destillation” by the warmth of the Sun.
It happens on Earth as well: the Earth is constantly losing Hydrogen to space, which is made by photo-dissociation by far UV radiation of water at high altitude where the light Hydrogen moves upwards and “boils” off and the much heavier Oxigen stays behind. (Do this 4.5 billion years and you are left with a sizable fraction of Oxigen; forget about those cyano bacteria that biologist think are responsible).
Missing magnetic field leads to missing atmosphere.
This is circumstantial evidence, but because it comes from an authoritative source, you are ready to believe it. I keep finding deference to authority from you on certain topics that aren’t your expertise. Why is this? Aren’t you immune to it yet?
Aren’t there other possibilities that aren’t ruled out?
Yes it is. It’s your fault Mark.
I hope you are suitably contrite. 😉
JDN says:
July 19, 2013 at 2:06 am
This is circumstantial evidence, but because it comes from an authoritative source, you are ready to believe it. I keep finding deference to authority from you on certain topics that aren’t your expertise. Why is this? Aren’t you immune to it yet?
Aren’t there other possibilities that aren’t ruled out?
I see no ‘deference’. This was a straight report of the NASA findings from the referenced NASA release. If you can hypothesize other possibilities that would provide the same atmospheric signature then you just wasted on opportunity to do so. I am sure other commenters will provide their own ideas – some quite forcefully; that is how this board works.
@Eric Simpson:
That comment is too much like the typical warmunist comments seen on any weather disaster (you know – too much rain, too much wind, not enough rain, not enough wind, too hot, too cold, etc) story in the local paper. No one will note it as sarcasm unless you have a history on the site of fighting that meme, and you may get a bunch of the usual chorus piling on praising it as the most insightful comment ever.
It is a sad comment on our education systems!.
Given the evidence of water erosion from rover pictures then a thicker atmosphere to support this water is a good clue. Isotope ratios will give another clue, based on the isotope ratios in our atmosphere, assuming that each planet shared the same ratios. gravity difference, rotation and orbital difference could make this assumption wrong. Atmospheric loss from the top could be due to the solar wind and the poor magnetic protection of Mars whereas our magnetic field gives a lot of protection from this.
I don’t see much difference with other nasa PR self-aggrandizing press releases. Scientists found that it’s more likely that Mars, as suspectedfrom times immemorable, has lost its atmosphere from the top, like all atmosphere-able planetary bodies are losing as we speak.
The news content appear to be zero or slightly slightly a positive number.
New insights? Yes. Solved? No way. Just one more phantasy coming from people with great instruments.
A more plausible explanation, by far, is that this is just the kind of atmosphere that any rock of Mars’s size will have.
Is it scientific reporting? Are they not supposed to report isotopic ratios, error bars included? Why to keep numbers resulting from research done on taxpayers’ money behind a paywall?
What does “heavy isotopes of carbon and oxygen are both enriched” actually mean?
Eric Simpson says:
July 19, 2013 at 1:29 am
That’s funny.
I gave up engaging with anyone on discus as I was going through email addresses faster than I was prepared to create them. Mostly down to taking no shit from Guardianista imbeciles but still losing the ‘right’ to free speech if someone disagrees with what is presented to them.
I almost always attempted to stay polite because it is easy to degenerate into the mouth of foul when your responder is faceless, in another country or on another planet.
It’s a press release, not a professional paper. Presumably the results will be written up and published, I hope not behind a paywall.
What’s interesting to me is what this might, or might not, say about the possibilities for terraforming Mars to make it habitable for humans. We’ll want to make the atmosphere thicker, by a large factor, with lots of oxygen, and make the surface a lot wetter. Steering a lot of icy comets into the planet might be a start. Then we bring in the plants. . .
/Mr Lynn
N.A.S.A. .. >=< never a straight ANSWER.
Here,s one:
For centuries civilizations from around the globe practised ritual killing, some less barbaric so. The time period is 10,000 to 12,000 BC. Paintings depict two celestial bodies in battle. There size to be two thirds of our moon. Further speculation from historians, speculates that the bodies were in fact the new arrival of Venus setting into a circumference orbit. Venus appeared to suck into her tail the whole atmosphere of Mars.
Space weather i guess.
PS look up.
I remember reading about Martian atmosphere evaporating into space since 1970s. OK, they found some confirmation of this old hypothesis. But why should it exclude any other factors?
Surely, Olympus Mons has something to do with the loss of Martian atmosphere. This gigantic bump on the surface could not have appeared without some catastrophic collision that stripped part of the Martian atmosphere. Also, Olympus Mons sticks out into the airless space, thus providing an additional conduit for constant convectional loss of atmosphere.
More BS from “scientists.”
It is totally clear that the original inhabitants of Mars destroyed their atmosphere due to their destructive mining, heavy industry, driving SUVs, coal fired power plants , deforestation, killing off the spotted owl by allowing unprecedented expansion of the barn owl, tossing plastic crap into their oceans, oil drilling, fracking, breathing, eating and merely existing.
Thank god some of those Martians were able to escape to the planet earth ( generally known as Bolsheviks) and established a peaceful , environmentally sustainable nation called the USSR, which achieved UNPRECEDENTED happiness and health until destroyed by the environmentally criminal USA in 1990.
mark fraser says:
July 19, 2013 at 1:15 am
Is it our fault?
—
Let’s blame it on Bush.
And the power plant used for this rover (Because the previous solar powered rover is “unreliable” because of dust landing on the solar panels)? Nuclear!
“These data are clear evidence of a substantially more massive atmosphere, hence a warmer, wetter Mars in the past than the cold, arid planet we find today.”
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Strange that this simple fact, that a more massive atmosphere is a warmer atmosphere, is not taken into account to explain why Venus is so hot, or to explain the faint sun paradox. Instead CO2 is used to explain Earth and Venus, but this is conveniently overlooked when talking about Mars because it also has a high CO2 atmosphere, yet Mars is cold.
To large degree, the temperature of Earth, Venus and Mars varies directly as the atmospheric pressure and the inverse square of the distance from the sun, regardless of atmospheric composition.
Of the three, Venus has the densest atmosphere, yet has no magnetic field to protect the atmosphere from the solar wind. Something overlooked in the explanation of how planets lose their atmosphere.
Venus has thick clouds which largely prevent solar radiation from heating the surface. This is confirmed in the fact that daytime and nighttime temperatures are largely the same on Venus. Without solar radiation warming the surface there would be little outgoing LWR to be returned by CO2 back radiation to the surface, according to GHG theory on earth. Yet clearly this explanation does not work when applied to Venus.
Why then does climate science suggest that cloud albedo reflects solar radiation to space on earth, while the evidence is very clear that this does not happen on Venus with its much denser cloud cover? The clouds on Venus clearly cannot reflect solar radiation to space. Otherwise, what heats the surface on Venus to temperatures higher than Mercury?
Undoubtedly, future explorations will find out that the reason that the atmosphere got so thin is that the early martians constructed massive wind turbines and blew it out into outer space. 😉
These scientists apparently believe that static conditions have lasted for billions of years by their statement “which scientists can deduce from proportions in the sun and other parts of the solar system.”
ferd berple says:
July 19, 2013 at 7:00 am
“The clouds on Venus clearly cannot reflect solar radiation to space. ”
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At any frequency? Then the bright morning star would be invisible.
Ed Zuiderwijk says:
July 19, 2013 at 1:31 am
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You can’t separate light gases from oxygen that isn’t there to begin with. The geochemists agree: banded iron, etc.
Alexander Feht says:
July 19, 2013 at 6:02 am
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According to my infallible sources (Wikipedia), Olympus Mons is a volcano, formed over millions of years, as shown by increasing (meteor) crater counts from peak to perimeter. Sounds like good evidence. –AGF
Looking for a single answer to this atmospheric riddle will lead to not finding the rest of the answers. The same thing happens with Earth’s climate; It must be not only the oceanic circulations, the Sun, continental drifts, or more CO2 each dominating the scene.
I see each and all components alternating chaotically to dominate for a while, then fade away.
The thin Martian atmosphere contains about 15.5 times more CO2 (.0062 bar) than does Earth’s (.0004 bar of dry air) 169 times thicker (101.3 kilopascals vs. 600 pascals surface pressure) & 5600 times more massive (1.4 x 10^21 kg vs. ~2.5 x 10^16 kg) atmosphere. The relative abundance of the magic gas there (950,000 ppmv) is 2375 times greater than here (400 ppmv).
The prevalence of heavier gases should give us a clue. The lighter ones are either not attracted strongly enough or are repelled. Even the oxygen found in rocks is heavier than on Earth.