Category Archives: NASA

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.

discovery, international space station, NASA, space exploration, space shuttle

As the Shuttle Missions Wind Down

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An Era is Slowly Ending…

The space shuttle Discovery as seen from the International Space Station. Courtesy NASA/USTREAM.

Those of you who were born in the early 1980s and after have always had sights like these to define what “near-Earth” space exploration looks like.  For the past 30 years, shuttle launches and delicate orbital ballets have been standard fare for us all to watch.

But, as we all know, that time and those missions are coming to an end. The last space shuttle flights are taking place in the next few months, and after that, the orbiters will fly no more. At least, that’s the current plan.

I’m not going to weigh in here on the relative merits of the next stage of U.S. space exploration hardware and missions, other than to say that we don’t have much tin being officially bent to take PEOPLE to space again anytime REAL soon.  Yes, there is the private sector activity, which I watch with great interest.  It will be interesting to see just how it all plays out. And, if it’s possible, I’ll try to make my way to space on a future “tourist flight” since I’m not likely to be picked as a “citizen journalist-astronaut” or “blogger-naut” or “Tweeter-naut” or whatever it is they’ll call them (if they come into being). Access to space, even 60 years after the first human flights, is still deemed a pretty risky and expensive proposition for all but the most fit (or, in the future probably, the most politically connected or wealthy).

Space shuttle as seen from above the ISS arm. Courtesy NASA/USTREAM

But, for all of us who “grew up” watching space shuttles loft to space, dance in orbit, take astronauts to the space station, deliver repair parts for Hubble Space Telescope, and many, many other important missions, these flights ARE the end of an era.  So, what can be more profound than to note that change in space flight status with a few views of today’s docking of Discovery with the International Space Station?  Enjoy!

As the shuttle slowly put itself into position for the docking, which took place at 1:14 CST today, I was reminded of a plane coming into the gate at an airport.  For all the hundreds of times I’ve landed at airports, and watched as the retractable jetway was steered out to nestle next to the plane by a gate agent, it never occurred to me how familiar it would  look as our own “space plane” would cuddle up next to the ISS.

Discovery passes under one of the station modules. Courtesy NASA/USTREAM.

But, there it was, earlier today, gliding into position just as if, for all the world, it was another flight landing and delivering a planeload of passengers and cargo. In fact, as I watched, the lyrics to the Alan Parsons Project song “I Can’t Look Down” from On Air, ran through my mind:  Another passenger, “Your baggage thank you sir”… even though I’m not afraid to fly and would just about give anything to go to space. I wish it were as commonplace as flying to LA or London or Paris is for many people. And that it cost about the same. I’d so be there.

A few minutes away from docking. Courtesy NASA/USTREAM

As I write this, the shuttle and ISS are docked together, and the astronauts will soon begin their work of ferrying new modules and equipment to the space station.  Right now they’re waiting while some relative motions and shaking die to down — a teachable moment in physics, actually, for anyone who wants to live and work in space some day (or has ever pondered what it would be like). Objects have mass, they gain momentum, and when you work with them in space, you have to take those factors into account.

In a sense it’s an everyday “fly to work, deliver the goods” kind of mission. But it’s also momentous. It’s the last time Discovery flies to the space station.  It’s the last mission for this venerable orbiter, which will return to Earth in a few days’ time and probably take up residence as an exhibit somewhere. And, for those of us who grew up in its era, it’s a surreal and unreal time — we know that this is all coming to an end. And, at least some of us are eagerly awaiting the next level of exploration.  Space travel is inevitable; the idea has mass and it’s gaining momentum. Now, how do we take them into account as we plan our next steps to space?