Daily Archives: March 8, 2011

jet Propulsion Laboratory, Mars, mars climate, Mars Reconnaissance Orbiter, NASA

Mars Missing Carbon Dioxide May Not Be Missing

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It Might Just Be Buried

This image shows the context for orbital observations of exposed rocks that had been buried an estimated 5 kilometers (3 miles) deep on Mars. It covers an area about 560 kilometers (350 miles) across, dominated by the Huygens crater, which is about the size of Wisconsin. The impact that excavated Huygens lifted material from far underground and piled some of it in the crater's rim. At about the 10 o'clock position around the rim of Huygens lies an unnamed crater about 35 kilometers (22 miles) in diameter that has punched into the uplifted rim material and exposed rocks containing carbonate minerals. The minerals were identified by observations with the Compact Reconnaissance Imaging Spectrometer for Mars on NASA's Mars Reconnaissance Orbiter. North is toward the top of this image, which is centered at 14 degrees south latitude, 304.4 degrees west longitude. The image combines topographical information from the Mars Orbiter Laser Altimeter instrument on NASA's Mars Global Surveyor with daytime infrared imaging by the Thermal Emission Imaging System camera on NASA's Mars Odyssey orbiter. Image credit: NASA/JPL-Caltech/Arizona State Univ. Click to enlarge.

I am a long-time Mars junkie. When I was growing up, I used to play at exploring Mars, and I probably expected to be living on the Red Planet some day.  Childhood dreams are like that — and the reality they lead to is a far different place.

For example, my “play” Mars looked a lot like Earth. Oh, the sky was red (I figured it had to have a red atmosphere).  It had red trees and red monsters and red food.  But, it never occurred to me that I wouldn’t be able to stand on its surface and breathe the air.  That’s a lesson I had to wait to learn when I grew up and studied the results of ongoing Mars missions. That was when I found out that Mars doesn’t have air like we do here on Earth. it’s got a carbon dioxide (CO2) atmosphere. A thin one, at that.  But, scientists suspect that the Red Planet used to have MORE atmosphere.

One of the recurring questions about Mars is the location of all its carbon dioxide. The Red Planet has a cold, thin, carbon-dioxide-rich atmosphere. Liquid water quicky boils away in that environment.

CO2 can get squirreled away in rocks, so-called carbonate minerals or carbonate layers. If they’re underground (under the surface), then that material isn’t easily found — unless you can dig it up and study it.

Essentially, that’s what planetary scientists using the Mars Reconnaissance Orbiter (MRO) have done. Oh, they haven’t used the orbiter to dig underground. They used it as it orbited above the surface to study rocks that have been dug up for us — by cratering events. Such an event was reported on at a meeting of planetary scientists this week.

The target studied was in Huygens crater, a basin 467 kilometers (290 miles) in diameter in the southern highlands of Mar. There are actually two cratering events in the area.  When Huygens was dug out by an incoming impactor, that action hoisted material from far underground. Then, the rim of Huygens, containing the earlier lifted material, was drilled into by a smaller, unnamed cratering event.

The occurrence of carbonate in association with the largest impact features suggests that it was buried by a few kilometers (or miles) of younger rocks, possibly including volcanic flows and fragmented material ejected from other, nearby impacts.

So, how does an impact dredge up rocks that show us what Mars was like in the past? When a meteor blasts into the surface of Mars (or any surface), it sends material flying away from the impact zone. That uncovers buried rocks. The MRO has an instrument that can study the chemical makeup of those rocks that have been uncovered.

At several places on Mars where cratering has exposed material from depths of about five kilometers (three miles) or more beneath the surface, MRO’s instrument has found evidence of carbonate minerals. This isn’t the first time carbonates have been found, but the finding does seem to confirm the speculated-on whereabouts of the missing Mars carbon.  And, if there are deeply buried carbonate layers are widespread on Mars, that would go a  long ways toward explaining what happened to the early Martian atmosphere, whihc was likely a much thicker carbon dioxide layer than we see on the Red Planet today.  In essence, the carbon that goes into formation of carbonate minerals can come from atmospheric carbon dioxide.

A dramatic change in atmospheric density remains one of the most intriguing possibilities about early Mars. Increasing evidence for liquid water on the surface of ancient Mars for extended periods continues to suggest that the atmosphere used to be much thicker.

The Technical Low-Down

The observations for this study were made using the high-resolution mode of the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on the Mars Reconnaissance Orbiter show spectral characteristics of calcium or iron carbonate at this site. Detections of clay minerals in lower-resolution mapping mode by CRISM had prompted closer examination with the spectrometer, and the carbonates are found near the clay minerals. Both types of minerals typically form in wet environments, which raises a number of questions about Mars’s early atmosphere and interactions of that atmosphere with the surface.

astronomy

An Endangered Writer Species

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And the Microbe That Probably Isn’t

I’m a science writer. I trained to be one. Spent years in graduate school, plus many more years honing my knowledge of the science I write about. I know how to look stuff up and find the meat of a story. Apparently, that makes me overqualified for the mainstream media, which doesn’t hire science writers (much) or bother to check on the veracity of a story before they commit it to 72-point-type screaming headlines in their endless 24-hour rush for news primacy.

As a science writer, I now find that I’m a member of an endangered species because science journalists have been purged from media organizations over the past decade.  For whatever reason, having an expert science writer actually … like… you know, write about science, isn’t important to many media outlets anymore. On CNN.com, for example, they merged science and technology. Important science stories get buried in with the latest Android apps discussion and iPad reviews. Yet, look at some media outlets and you’ll see them swimming in wads of sports writers and clutches of fashion and celebrity gossip editors and pestilences of political commentary, sometimes written by people who don’t seem to have learned the basic rules of journalism.

Science is a HUGE part of our lives. We are swimming in the products of science each day. Yet, our largest, most influential media outlets seem to be afraid of it. Or want to write about science the way way they write about celebrity marriage disasters. What ever happened to having expert science writers do their jobs?

I swear, it seems easier for some outlets to publish news about the latest Charlie Sheen outrage or the ongoing pronouncements of doom from hysterical politicians (many of whom don’t know what they’re talking about), or stories that are really nothing more than fluff and nonsense. Sad to say, science gets the breathless treatment. Or it gets told as a narrative that’s framed by an editor’s limited understanding of the subject. Rarely does it seem that news editors check the veracity of what they’re publishing in science stories. I have to ask myself, if they get it wrong about science so much, what ELSE are they getting wrong? What else aren’t they publishing?

Last week a scientist announced that he had found what he was sure was life in a meteorite. He published his results in a “journal” that seems to be a front for conspiracy theorists and whackadoos. Why he did that, I have no idea. I won’t even speculate since I don’t have any insight. But, he did. And, of course, the mainstream media around the world, led by the spectacular-fail folks at Fox News, carried the “story” with breathless hype, screeching headlines and — as far as I can tell — very little research to see if this guy’s claims were even scientifically accurate.

A seasoned science reporter would have caught the nuances immediately and helped her or his media outlet run a balanced story. There’s an interesting entry over at the Columbia Journalism Review that quotes Knight Science Journalism Tracker Charlie Petit talking about the over-the-top coverage we saw last week, “That kind of hyperbolic gumption alone ought to set most reporter’s smell-a-rat instincts to high alert.” And whether it was the editor’s note or the memory of other astrobiology stories gone wrong, on high alert they were.”

I know when I read the first story and the release, I was immediately skeptical of the claims that the microbes in the rock were found in space. Especially after I read that the rock had been on Earth for many years — plenty of time for Earth-based life to contaminate it. I knew from geology class, for example, that rock is porous — and that microbes can get into rocks pretty easily. Had I been a science reporter at a reputable news outlet, I would have immediately called up other experts to get the skinny on the science.

Of course, the breathless reporting from Fox, et al, left the scientists who actually know the field to play catch-up in explaining the story.  Unfortunately, now that the corrective stories are coming out, the mainstream media has moved on to the next fluffy story and there’ll be nothing more said.

Luckily, for the discerning folk who want to learn more about science than what shows up on Fox News or the National Enquirer, there ARE science writers like me, Phil Plait, Nancy Atkinson at Universe Today, and many others who ARE reputable and thoughtful and can leap up and write about these stories with a measure of authority.  We’re here in the blogs, and the online outlets that specialize in science. You won’t always find us in the mainstream media, although some outlets are starting to syndicate some of us into their sites. (In my case, my work is appearing on SpaceTimesNews and occasionally on Christian Science Monitor’s Cool Astronomy Blog showcase ).  Unluckily, the mainstream READER who wants to get a good, honest science story isn’t always going to know how to find us (or other reputable sci-journalists).

What bothers me is that if the mainstream media isn’t getting this science correct, how do we know they are reporting medical science correctly? Or telling the whole story of a political event?  Or reporting world news properly? We don’t. Remember, we all watched as business writers missed out on the Wall Street depredations during the Bush years. So, there’s a disconnect not just in science writing but other areas. If the level of science coverage that is being foisted on us by the likes of Fox and other outlets is any indication, you have to wonder just how badly they’re screwing up other news, too.

It used to be that journalists checked their facts, checked out a story, and could tell the difference between bravo sierra and news.  In light of this most recent news debacle over the microbes that probably aren’t microbes, it’s clear that those of us who trained to do our jobs are in a rapidly vanishing minority, because you didn’t see much good science writing in the big media. You saw fluff and breathlessness.  And you, the readers, the taxpayers, the folks who live in an increasingly technological world, lose out when unknowledgeable writers jump on stories without any thought to making sure they’re accurate, or even worth bothering with.